From 8f4fdb405a8470b9d06ab14ced120da89b213e82 Mon Sep 17 00:00:00 2001 From: Stephan Bergmann Date: Mon, 7 Oct 2019 17:31:02 +0200 Subject: New loplugin:classmemaccess ...to complement and improve upon GCC's -Wclass-memaccess. See the comment at the head of compilerplugins/clang/classmemaccess.cxx for details. (It is not yet clear to me whether we would want to get this upstreamed into Clang.) 35d21e4bf6f66b3bbc7a44fcf184cb721b524a94 "Remove redundant memsets" was a case that benefited from looking through toplevel casts to void*. (Though the code in include/basic/sbxvar.hxx needs a slightly more verbose way to deliberately silence the warning now.) d03041e19215592f21ba1222d3cfa29e1f94260a "Drop bogus memsets" is one example of various cases that GCC -Wclass-memaccess failed to catch due to the use of array instead of pointer types. Change-Id: I6a9bfc34e3536834af35fdf4fb7ceeb31f31f8c0 Reviewed-on: https://gerrit.libreoffice.org/80421 Tested-by: Jenkins Reviewed-by: Stephan Bergmann --- compilerplugins/clang/test/classmemaccess.cxx | 36 +++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 compilerplugins/clang/test/classmemaccess.cxx (limited to 'compilerplugins/clang/test/classmemaccess.cxx') diff --git a/compilerplugins/clang/test/classmemaccess.cxx b/compilerplugins/clang/test/classmemaccess.cxx new file mode 100644 index 000000000000..05bb457f87e3 --- /dev/null +++ b/compilerplugins/clang/test/classmemaccess.cxx @@ -0,0 +1,36 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +#include + +void f(struct Incomplete* p1, struct S* p2); + +struct S +{ + S(); +}; + +void f(struct Incomplete* p1, struct S* p2) +{ + S s; + // expected-error@+1 {{writing to an object of non-trivial type 'S'; use assignment instead [loplugin:classmemaccess]}} + std::memset(&s, 0, sizeof s); + // expected-error@+1 {{writing to an object of non-trivial type 'S'; use assignment instead [loplugin:classmemaccess]}} + std::memset(static_cast(&s), 0, sizeof s); + auto const disableWarning = static_cast(&s); + std::memset(disableWarning, 0, sizeof s); + S a[1][1]; + // expected-error@+1 {{writing to an object of non-trivial type 'S'; use assignment instead [loplugin:classmemaccess]}} + std::memset(a, 0, sizeof a); + std::memset(p1, 0, 10); // conservatively assume Incomplete may be trivial + // expected-error@+1 {{writing to an object of non-trivial type 'S'; use assignment instead [loplugin:classmemaccess]}} + std::memset(p2, 0, 10); +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */ -- cgit