From patchwork Thu Mar 12 08:59:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 11433611 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2B22E92C for ; Thu, 12 Mar 2020 09:01:45 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 0968F20691 for ; Thu, 12 Mar 2020 09:01:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0968F20691 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jCJhm-0000iQ-Ep; Thu, 12 Mar 2020 09:00:38 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jCJhl-0000i2-5w for xen-devel@lists.xenproject.org; Thu, 12 Mar 2020 09:00:37 +0000 X-Inumbo-ID: ebeade60-643f-11ea-92cf-bc764e2007e4 Received: from relay.sw.ru (unknown [185.231.240.75]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id ebeade60-643f-11ea-92cf-bc764e2007e4; Thu, 12 Mar 2020 09:00:29 +0000 (UTC) Received: from vovaso.qa.sw.ru ([10.94.3.0] helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1jCJgt-0004Ve-Hl; Thu, 12 Mar 2020 11:59:43 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org Date: Thu, 12 Mar 2020 11:59:28 +0300 Message-Id: <20200312085936.9552-3-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20200312085936.9552-1-vsementsov@virtuozzo.com> References: <20200312085936.9552-1-vsementsov@virtuozzo.com> MIME-Version: 1.0 Subject: [Xen-devel] [PATCH v9 02/10] scripts: Coccinelle script to use ERRP_AUTO_PROPAGATE() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , vsementsov@virtuozzo.com, Laszlo Ersek , qemu-block@nongnu.org, Paul Durrant , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Christian Schoenebeck , Greg Kurz , armbru@redhat.com, Stefano Stabellini , Gerd Hoffmann , Stefan Hajnoczi , Anthony Perard , xen-devel@lists.xenproject.org, Max Reitz , Eric Blake , Michael Roth , Stefan Berger Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Script adds ERRP_AUTO_PROPAGATE macro invocation where appropriate and does corresponding changes in code (look for details in include/qapi/error.h) Usage example: spatch --sp-file scripts/coccinelle/auto-propagated-errp.cocci \ --macro-file scripts/cocci-macro-file.h --in-place --no-show-diff \ --max-width 80 FILES... Signed-off-by: Vladimir Sementsov-Ogievskiy --- Cc: Eric Blake Cc: Kevin Wolf Cc: Max Reitz Cc: Greg Kurz Cc: Christian Schoenebeck Cc: Stefano Stabellini Cc: Anthony Perard Cc: Paul Durrant Cc: Stefan Hajnoczi Cc: "Philippe Mathieu-Daudé" Cc: Laszlo Ersek Cc: Gerd Hoffmann Cc: Stefan Berger Cc: Markus Armbruster Cc: Michael Roth Cc: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org Cc: xen-devel@lists.xenproject.org scripts/coccinelle/auto-propagated-errp.cocci | 327 ++++++++++++++++++ include/qapi/error.h | 3 + MAINTAINERS | 1 + 3 files changed, 331 insertions(+) create mode 100644 scripts/coccinelle/auto-propagated-errp.cocci diff --git a/scripts/coccinelle/auto-propagated-errp.cocci b/scripts/coccinelle/auto-propagated-errp.cocci new file mode 100644 index 0000000000..7dac2dcfa4 --- /dev/null +++ b/scripts/coccinelle/auto-propagated-errp.cocci @@ -0,0 +1,327 @@ +// Use ERRP_AUTO_PROPAGATE (see include/qapi/error.h) +// +// Copyright (c) 2020 Virtuozzo International GmbH. +// +// This program is free software; you can redistribute it and/or +// modify it under the terms of the GNU General Public License as +// published by the Free Software Foundation; either version 2 of the +// License, or (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program. If not, see +// . +// +// Usage example: +// spatch --sp-file scripts/coccinelle/auto-propagated-errp.cocci \ +// --macro-file scripts/cocci-macro-file.h --in-place \ +// --no-show-diff --max-width 80 FILES... +// +// Note: --max-width 80 is needed because coccinelle default is less +// than 80, and without this parameter coccinelle may reindent some +// lines which fit into 80 characters but not to coccinelle default, +// which in turn produces extra patch hunks for no reason. + +// Switch unusual Error ** parameter names to errp +// (this is necessary to use ERRP_AUTO_PROPAGATE). +// +// Disable optional_qualifier to skip functions with +// "Error *const *errp" parameter. +// +// Skip functions with "assert(_errp && *_errp)" statement, because +// that signals unusual semantics, and the parameter name may well +// serve a purpose. (like nbd_iter_channel_error()). +// +// Skip util/error.c to not touch, for example, error_propagate() and +// error_propagate_prepend(). +@ depends on !(file in "util/error.c") disable optional_qualifier@ +identifier fn; +identifier _errp != errp; +@@ + + fn(..., +- Error **_errp ++ Error **errp + ,...) + { +( + ... when != assert(_errp && *_errp) +& + <... +- _errp ++ errp + ...> +) + } + +// Add invocation of ERRP_AUTO_PROPAGATE to errp-functions where +// necessary +// +// Note, that without "when any" the final "..." does not mach +// something matched by previous pattern, i.e. the rule will not match +// double error_prepend in control flow like in +// vfio_set_irq_signaling(). +// +// Note, "exists" says that we want apply rule even if it matches not +// on all possible control flows (otherwise, it will not match +// standard pattern when error_propagate() call is in if branch). +@ disable optional_qualifier exists@ +identifier fn, local_err; +symbol errp; +@@ + + fn(..., Error **errp, ...) + { ++ ERRP_AUTO_PROPAGATE(); + ... when != ERRP_AUTO_PROPAGATE(); +( +( + error_append_hint(errp, ...); +| + error_prepend(errp, ...); +| + error_vprepend(errp, ...); +) + ... when any +| + Error *local_err = NULL; + ... +( + error_propagate_prepend(errp, local_err, ...); +| + error_propagate(errp, local_err); +) + ... +) + } + + +// Match functions with propagation of local error to errp. +// We want to refer these functions in several following rules, but I +// don't know a proper way to inherit a function, not just its name +// (to not match another functions with same name in following rules). +// Not-proper way is as follows: rename errp parameter in functions +// header and match it in following rules. Rename it back after all +// transformations. +// +// The simplest case of propagation scheme is single definition of +// local_err with at most one error_propagate_prepend or +// error_propagate on each control-flow. Still, we want to match more +// complex schemes too. We'll warn them with help of further rules. +@rule1 disable optional_qualifier exists@ +identifier fn, local_err; +symbol errp; +@@ + + fn(..., Error ** +- errp ++ ____ + , ...) + { + ... + Error *local_err = NULL; + ... +( + error_propagate_prepend(errp, local_err, ...); +| + error_propagate(errp, local_err); +) + ... + } + + +// Warn several Error * definitions. +@check1 disable optional_qualifier exists@ +identifier fn = rule1.fn, local_err, local_err2; +@@ + + fn(..., Error ** ____, ...) + { + ... + Error *local_err = NULL; + ... when any + Error *local_err2 = NULL; + ... when any + } + +@ script:python @ +fn << check1.fn; +@@ + +print('Warning: function {} has several definitions of ' + 'Error * local variable'.format(fn)) + +// Warn several propagations in control flow. +@check2 disable optional_qualifier exists@ +identifier fn = rule1.fn; +symbol errp; +position p1, p2; +@@ + + fn(..., Error ** ____, ...) + { + ... +( + error_propagate_prepend(errp, ...);@p1 +| + error_propagate(errp, ...);@p1 +) + ... +( + error_propagate_prepend(errp, ...);@p2 +| + error_propagate(errp, ...);@p2 +) + ... when any + } + +@ script:python @ +fn << check2.fn; +p1 << check2.p1; +p2 << check2.p2; +@@ + +print('Warning: function {} propagates to errp several times in ' + 'one control flow: at {}:{} and then at {}:{}'.format( + fn, p1[0].file, p1[0].line, p2[0].file, p2[0].line)) + +// Convert special case with goto separately. +// I tried merging this into the following rule the obvious way, but +// it made Coccinelle hang on block.c +// +// Note interesting thing: if we don't do it here, and try to fixup +// "out: }" things later after all transformations (the rule will be +// the same, just without error_propagate() call), coccinelle fails to +// match this "out: }". +@ disable optional_qualifier@ +identifier rule1.fn, rule1.local_err, out; +symbol errp; +@@ + + fn(..., Error ** ____, ...) + { + <... +- goto out; ++ return; + ...> +- out: +- error_propagate(errp, local_err); + } + +// Convert most of local_err related stuff. +// +// Note, that we update everything related to matched by rule1 +// function name and local_err name. We may match something not +// related to the pattern matched by rule1. For example, local_err may +// be defined with the same name in different blocks inside one +// function, and in one block follow the propagation pattern and in +// other block doesn't. Or we may have several functions with the same +// name (for different configurations). +// +// Note also that errp-cleaning functions +// error_free_errp +// error_report_errp +// error_reportf_errp +// warn_report_errp +// warn_reportf_errp +// are not yet implemented. They must call corresponding Error* - +// freeing function and then set *errp to NULL, to avoid further +// propagation to original errp (consider ERRP_AUTO_PROPAGATE in use). +// For example, error_free_errp may look like this: +// +// void error_free_errp(Error **errp) +// { +// error_free(*errp); +// *errp = NULL; +// } +@ disable optional_qualifier exists@ +identifier rule1.fn, rule1.local_err; +expression list args; +symbol errp; +@@ + + fn(..., Error ** ____, ...) + { + <... +( +- Error *local_err = NULL; +| + +// Convert error clearing functions +( +- error_free(local_err); ++ error_free_errp(errp); +| +- error_report_err(local_err); ++ error_report_errp(errp); +| +- error_reportf_err(local_err, args); ++ error_reportf_errp(errp, args); +| +- warn_report_err(local_err); ++ warn_report_errp(errp); +| +- warn_reportf_err(local_err, args); ++ warn_reportf_errp(errp, args); +) +?- local_err = NULL; + +| +- error_propagate_prepend(errp, local_err, args); ++ error_prepend(errp, args); +| +- error_propagate(errp, local_err); +| +- &local_err ++ errp +) + ...> + } + +// Convert remaining local_err usage. For example, different kinds of +// error checking in if conditionals. We can't merge this into +// previous hunk, as this conflicts with other substitutions in it (at +// least with "- local_err = NULL"). +@ disable optional_qualifier@ +identifier rule1.fn, rule1.local_err; +symbol errp; +@@ + + fn(..., Error ** ____, ...) + { + <... +- local_err ++ *errp + ...> + } + +// Always use the same pattern for checking error +@ disable optional_qualifier@ +identifier rule1.fn; +symbol errp; +@@ + + fn(..., Error ** ____, ...) + { + <... +- *errp != NULL ++ *errp + ...> + } + +// Revert temporary ___ identifier. +@ disable optional_qualifier@ +identifier rule1.fn; +@@ + + fn(..., Error ** +- ____ ++ errp + , ...) + { + ... + } diff --git a/include/qapi/error.h b/include/qapi/error.h index 30140d9bfe..56c133520d 100644 --- a/include/qapi/error.h +++ b/include/qapi/error.h @@ -214,6 +214,9 @@ * } * ... * } + * + * For mass-conversion use script + * scripts/coccinelle/auto-propagated-errp.cocci */ #ifndef ERROR_H diff --git a/MAINTAINERS b/MAINTAINERS index 857f969aa1..047f1b9714 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1998,6 +1998,7 @@ F: include/qemu/error-report.h F: qapi/error.json F: util/error.c F: util/qemu-error.c +F: scripts/coccinelle/*err*.cocci GDB stub M: Alex Bennée