From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=ALL_TRUSTED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NO_DNS_FOR_FROM,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.6 Received: from localhost.localdomain (unknown [138.197.159.143]) by gnuweeb.org (Postfix) with ESMTPSA id BB6947ED99; Mon, 9 May 2022 06:54:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gnuweeb.org; s=default; t=1652079291; bh=S02Hmy2ySu7f3PmzWcyNC62xCF6tNDxQIeCYDbJJgL8=; h=From:To:Cc:Subject:Date:From; b=G2IVrpE8mpPZ6ZJ3DtpuPGtHCD7jbj2Wp3e2vG25GZDwMwdBR+pX7u5Dxk6FSBlea 1/Bpxki+2qV/qtRWzpfXDZJFMGgmUn/MrBcgZm5FzoIh34EzzjQrHFYIG1fmKCO/7d lyD9d04NrbHidiAzbde2tymzUnWR/oPaskLAtz5R1Pa4mipoFaVY8/fyDxbmJylh/O jgvyPXPIXrjMS0+OnqmTyvqInGQ55iYnvq8ou4m3m4lZLzc8I56Yj93qle+cpNsUSD yMaQmt2JU22kcqoie+4GCZePosrqvWXCZaCs6+58MZ9fN6uq0goDTaZ2AQdTAphWHS SUOIzcwG7tWrw== From: Alviro Iskandar Setiawan To: Ammar Faizi Cc: GNU/Weeb Mailing List , Linux Kernel Mailing List , Alviro Iskandar Setiawan Subject: [PATCH 0/1] Add format attribute to enable printf warnings Date: Mon, 9 May 2022 06:54:44 +0000 Message-Id: <20220509065445.3912334-1-alviro.iskandar@gnuweeb.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-Id: Hi Ammar, When we use printf and fprintf functions from nolibc, we don't get any warning from the compiler if we have wrong arguments, for example the following calls will compile silently: ``` printf("%s %s\n", "aaa"); fprintf(stdout, "%s %s\n", "xxx", 1); ``` Those calls are undefined behavior. We can catch it at compile time by adding format attribute to those function declarations. After this patch, we get the following warnings: ``` warning: format `%s` expects a matching `char *` argument [-Wformat=] warning: format `%s` expects argument of type `char *`, but argument 4 has type `int` [-Wformat=] ``` Signed-off-by: Alviro Iskandar Setiawan --- Alviro Iskandar Setiawan (1): tools/nolibc/stdio: Add format attribute to enable printf warnings tools/include/nolibc/stdio.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) base-commit: 2fbaf4ddb5e2f64a565247683093b869b5b3f792 prerequisite-patch-id: 1bcffd448f6984eee80d86560af19672cd4ae716 prerequisite-patch-id: 3e31c80bd4dd532e30b4bba76e5d98647e21184b prerequisite-patch-id: 34e531967a67791d5b3c3e071527de7235715906 prerequisite-patch-id: 14105c6ae9dcc068ddf12a7c1bf431066199b813 prerequisite-patch-id: 4299173943ea579f538da00488fb1a7b1a690a79 prerequisite-patch-id: dd85164f2ec9eb8cea64ab801abac614f9d0c8f5 prerequisite-patch-id: 2c1b940635d1564e26b9959eb57cf9fa6983cb2f prerequisite-patch-id: 8b1b453d855c9b8081353ffbddd03f6cfcfa2ab6 -- Alviro Iskandar Setiawan