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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4324eaa08d9sm872464f8f.30.2025.12.18.12.26.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Dec 2025 12:26:46 -0800 (PST) Date: Thu, 18 Dec 2025 20:26:44 +0000 From: David Laight To: Vincent Mailhol Cc: Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Chris Mason , David Sterba , Linus Torvalds , linux-kbuild@vger.kernel.org, linux-sparse@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, dri-devel@lists.freedesktop.org, linux-btrfs@vger.kernel.org Subject: Re: [PATCH 0/2] kbuild: remove gcc's -Wtype-limits Message-ID: <20251218202644.0bd24aa8@pumpkin> In-Reply-To: <20251218-remove_wtype-limits-v1-0-735417536787@kernel.org> References: <20251218-remove_wtype-limits-v1-0-735417536787@kernel.org> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 18 Dec 2025 19:50:00 +0100 Vincent Mailhol wrote: > I often read on the mailing list people saying "who cares about W=2 > builds anyway?". At least I do. Not that I want to fix all of them, > but on some occasions, such as new driver submissions, I have often > found a couple valid diagnostics in the W=2 output. > > That said, the annoying thing is that W=2 is heavily polluted by one > warning: -Wtype-limits. Try a gcc W=2 build on any file and see the > results for yourself. I suspect this to be the reason why so few > people are using W=2. One possibility is to conditionally add _Pragma() inside #defines to turn off the warning for the main false positives (I guess all the BUILD_BUG_xxxx and statically_true are the main ones). But don't 'bloat' the #define expansions for normal builds. David