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[37.110.38.130]) by smtp.googlemail.com with ESMTPSA id i187sm62263lfd.65.2020.09.01.00.15.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Sep 2020 00:15:45 -0700 (PDT) From: Denis Efremov To: julia.lawall@inria.fr Cc: Denis Efremov , cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org, Kees Cook , "Gustavo A . R . Silva" Subject: [PATCH v2] coccinelle: misc: add uninitialized_var.cocci script Date: Tue, 1 Sep 2020 10:15:33 +0300 Message-Id: <20200901071533.2725-1-efremov@linux.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200811210127.11889-1-efremov@linux.com> References: <20200811210127.11889-1-efremov@linux.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 63a0895d960a ("compiler: Remove uninitialized_var() macro") and commit 4b19bec97c88 ("docs: deprecated.rst: Add uninitialized_var()") removed uninitialized_var() and deprecated it. The purpose of this script is to prevent new occurrences of open-coded variants of uninitialized_var(). Cc: Kees Cook Cc: Gustavo A. R. Silva Signed-off-by: Denis Efremov --- Changes in v2: - Documentation cited in the script's description - kernel.org link added to the diagnostics messages - "T *var = &var;" pattern removed - "var =@p var", "var =@p *(&(var))" patterns added .../coccinelle/misc/uninitialized_var.cocci | 51 +++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 scripts/coccinelle/misc/uninitialized_var.cocci diff --git a/scripts/coccinelle/misc/uninitialized_var.cocci b/scripts/coccinelle/misc/uninitialized_var.cocci new file mode 100644 index 000000000000..8fa845cefe11 --- /dev/null +++ b/scripts/coccinelle/misc/uninitialized_var.cocci @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0-only +/// +/// Please, don't reintroduce uninitialized_var(). +/// From Documentation/process/deprecated.rst: +/// For any compiler warnings about uninitialized variables, just add +/// an initializer. Using warning-silencing tricks is dangerous as it +/// papers over real bugs (or can in the future), and suppresses unrelated +/// compiler warnings (e.g. "unused variable"). If the compiler thinks it +/// is uninitialized, either simply initialize the variable or make compiler +/// changes. Keep in mind that in most cases, if an initialization is +/// obviously redundant, the compiler's dead-store elimination pass will make +/// sure there are no needless variable writes. +/// +// Confidence: High +// Copyright: (C) 2020 Denis Efremov ISPRAS +// Options: --no-includes --include-headers +// + +virtual context +virtual report +virtual org + +@r@ +identifier var; +type T; +position p; +@@ + +( +* T var =@p var; +| +* T var =@p *(&(var)); +| +* var =@p var +| +* var =@p *(&(var)) +) + +@script:python depends on report@ +p << r.p; +@@ + +coccilib.report.print_report(p[0], + "WARNING this kind of initialization is deprecated (https://www.kernel.org/doc/html/latest/process/deprecated.html#uninitialized-var)") + +@script:python depends on org@ +p << r.p; +@@ + +coccilib.org.print_todo(p[0], + "WARNING this kind of initialization is deprecated (https://www.kernel.org/doc/html/latest/process/deprecated.html#uninitialized-var)") -- 2.26.2