From nobody Thu Sep 11 12:57:46 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ABD0AC00528 for ; Mon, 7 Aug 2023 15:37:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230435AbjHGPhY (ORCPT ); Mon, 7 Aug 2023 11:37:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230472AbjHGPhT (ORCPT ); Mon, 7 Aug 2023 11:37:19 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DF3919A9; Mon, 7 Aug 2023 08:37:11 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AA36E61E2C; Mon, 7 Aug 2023 15:37:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68116C433C7; Mon, 7 Aug 2023 15:37:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691422630; bh=Tv6VzIDd4SIlArHBmIHp9VMuLmiykxV8wOzCt+lQsFg=; h=From:Date:Subject:To:Cc:From; b=pYDj8uco4GtRbiwzZQvDQuZqaghPK/L/nkZ2pZfUDnIp7eOfWyTy/bnDqck2DL0gE 8/J8KohuKXxPgOci7K/A8KXF6nnLlgrH1pHUpNk8WGaZtjV1crio+MHCk8fjkQBjPb CY1iec/HzpPhW3xRDtkKQ+TBmSba1u33OsXGvvv1NKSpJnDCZlzFSg+Ukjgldo+khW hkBW83rtyKiJj5XWDeHSlFTKBJZH9vPpe7hUyAnitqiN0abMEoeBCyXVJwvI15Mck7 IUf3QHQ/Zl76gPtJEiy8nLKVqbBbA+2zPP6WvhNW+FOwHpha5VtoxoPOMx7osRLVXH uIYxVPT/mrtUg== From: Nathan Chancellor Date: Mon, 07 Aug 2023 08:36:28 -0700 Subject: [PATCH v2] lib: test_scanf: Add explicit type cast to result initialization in test_number_prefix() MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20230807-test_scanf-wconstant-conversion-v2-1-839ca39083e1@kernel.org> X-B4-Tracking: v=1; b=H4sIAHsP0WQC/42NXQrCMBCEr1L22ZU2rdT65D2kSH42bVAS2YSol N7dtCfwbb6B+WaBSOwowqVagCm76IIvIA4V6Fn6idCZwiBq0dbnusVEMd2jlt7iWwcfk/QJS8j E2xbN0JNVtlXqZKBYXkzWffaH21h4djEF/u6Hudna/925wQb7zshh6AwZpa8PYk/PY+AJxnVdf 2Pr4zvPAAAA To: pmladek@suse.com, rostedt@goodmis.org Cc: senozhatsky@chromium.org, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, ndesaulniers@google.com, trix@redhat.com, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, stable@vger.kernel.org, Nathan Chancellor X-Mailer: b4 0.13-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2585; i=nathan@kernel.org; h=from:subject:message-id; bh=Tv6VzIDd4SIlArHBmIHp9VMuLmiykxV8wOzCt+lQsFg=; b=owGbwMvMwCEmm602sfCA1DTG02pJDCkX+ZfeXZ6ZtHxLf+QKvwd7Tp7avsChcfJjk+TXPnrKr //+fHzwV0cpC4MYB4OsmCJL9WPV44aGc84y3jg1CWYOKxPIEAYuTgGYiMJORoav2WeXuqfc1LXM uqpxcbGBc36moElHXIvRPN9Z00otxX0Y/kpIswrm9WVFdX77Iffx5Yzku3Ou3OPevTddYY1pq5N AOA8A X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A recent change in clang allows it to consider more expressions as compile time constants, which causes it to point out an implicit conversion in the scanf tests: lib/test_scanf.c:661:2: warning: implicit conversion from 'int' to 'unsig= ned char' changes value from -168 to 88 [-Wconstant-conversion] 661 | test_number_prefix(unsigned char, "0xA7", "%2hhx%hh= x", 0, 0xa7, 2, check_uchar); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/test_scanf.c:609:29: note: expanded from macro 'test_number_prefix' 609 | T result[2] =3D {~expect[0], ~expect[1]}; = \ | ~ ^~~~~~~~~~ 1 warning generated. The result of the bitwise negation is the type of the operand after going through the integer promotion rules, so this truncation is expected but harmless, as the initial values in the result array get overwritten by _test() anyways. Add an explicit cast to the expected type in test_number_prefix() to silence the warning. There is no functional change, as all the tests still pass with GCC 13.1.0 and clang 18.0.0. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/1899 Link: https://github.com/llvm/llvm-project/commit/610ec954e1f81c0e8fcadedcd= 25afe643f5a094e Suggested-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Reviewed-by: Petr Mladek --- Changes in v2: - Add spaces in initializer to match result (Andy) - Add 'Cc: stable', as builds with CONFIG_WERROR will be broken, such as allmodconfig - Link to v1: https://lore.kernel.org/r/20230803-test_scanf-wconstant-conve= rsion-v1-1-74da994dedbc@kernel.org --- lib/test_scanf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/test_scanf.c b/lib/test_scanf.c index b620cf7de503..a2707af2951a 100644 --- a/lib/test_scanf.c +++ b/lib/test_scanf.c @@ -606,7 +606,7 @@ static void __init numbers_slice(void) #define test_number_prefix(T, str, scan_fmt, expect0, expect1, n_args, fn)= \ do { \ const T expect[2] =3D { expect0, expect1 }; \ - T result[2] =3D {~expect[0], ~expect[1]}; \ + T result[2] =3D { (T)~expect[0], (T)~expect[1] }; \ \ _test(fn, &expect, str, scan_fmt, n_args, &result[0], &result[1]); \ } while (0) --- base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4 change-id: 20230803-test_scanf-wconstant-conversion-d97efbf3bb5d Best regards, --=20 Nathan Chancellor