coccinelle: misc: add uninitialized_var.cocci script

uninitialized_var() macro was removed from the sources [1] and
other warning-silencing tricks were deprecated [2]. The purpose of this
cocci script is to prevent new occurrences of uninitialized_var()
open-coded variants.

[1] commit 63a0895d96 ("compiler: Remove uninitialized_var() macro")
[2] commit 4b19bec97c ("docs: deprecated.rst: Add uninitialized_var()")

Cc: Kees Cook <keescook@chromium.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
This commit is contained in:
Denis Efremov 2020-09-01 12:48:12 +03:00 committed by Julia Lawall
parent 5e0c074e5b
commit 7c9dc603d5

View File

@ -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)")