From patchwork Tue Jun 27 15:29:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathieu Desnoyers X-Patchwork-Id: 13294674 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 6CFE9C001DF for ; Tue, 27 Jun 2023 15:29:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231246AbjF0P3p (ORCPT ); Tue, 27 Jun 2023 11:29:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231924AbjF0P3n (ORCPT ); Tue, 27 Jun 2023 11:29:43 -0400 Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1309E2942; Tue, 27 Jun 2023 08:29:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1687879779; bh=oKkXMwl9CppgPR3HEtDQfgVFXUAQ6EoIiQSv7ieSscM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hXNcy6nCTJIqA16UhPSgfyd6AmV61FoDTnapkgcJ42vPjzC5RL+3HyDJCfADcjXKz qhH8QxzBY3MBiUTblRqiY2gzlwUztpGUHOnefGoLogsru3uDCxZx9GV6NMw2u3U87k uZFgwcGLpCBzuzh+iIJ3Egtrv3EU+t6PGpl8e7vJhLQpUvr2/Oxi9tNLFbqLDWx6dB QEq7SIdMs/UB2+4uZtMup+3ZAMWza3WUDlYXJPN1IkRZBpxhVPGaeG7kgtRjkAc+qv bZsKJrTeuD11edopYYKU10/3SBu7m7Uwb+yVAQen3jLIoFlRHNfUtFir9yzWxURvyg jSAzD8CS+++YA== Received: from localhost.localdomain (192-222-143-198.qc.cable.ebox.net [192.222.143.198]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4Qr7tW19F9z19RQ; Tue, 27 Jun 2023 11:29:39 -0400 (EDT) From: Mathieu Desnoyers To: Shuah Khan Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Peter Zijlstra , "Paul E . McKenney" , Boqun Feng , "H . Peter Anvin" , Paul Turner , linux-api@vger.kernel.org, linux-kselftest@vger.kernel.org, Mathieu Desnoyers Subject: [PATCH 2/4] selftests/rseq: Implement rseq_unqual_scalar_typeof Date: Tue, 27 Jun 2023 11:29:21 -0400 Message-Id: <20230627152923.133238-3-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230627152923.133238-1-mathieu.desnoyers@efficios.com> References: <20230627152923.133238-1-mathieu.desnoyers@efficios.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Allow defining variables and perform cast with a typeof which removes the volatile and const qualifiers. This prevents declaring a stack variable with a volatile qualifier within a macro, which would generate sub-optimal assembler. This is imported from the "librseq" project. Signed-off-by: Mathieu Desnoyers --- tools/testing/selftests/rseq/compiler.h | 26 +++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/tools/testing/selftests/rseq/compiler.h b/tools/testing/selftests/rseq/compiler.h index f47092bddeba..49d62fbd6dda 100644 --- a/tools/testing/selftests/rseq/compiler.h +++ b/tools/testing/selftests/rseq/compiler.h @@ -33,4 +33,30 @@ #define RSEQ_COMBINE_TOKENS(_tokena, _tokenb) \ RSEQ__COMBINE_TOKENS(_tokena, _tokenb) +#ifdef __cplusplus +#define rseq_unqual_scalar_typeof(x) \ + std::remove_cv::type>::type +#else +#define rseq_scalar_type_to_expr(type) \ + unsigned type: (unsigned type)0, \ + signed type: (signed type)0 + +/* + * Use C11 _Generic to express unqualified type from expression. This removes + * volatile qualifier from expression type. + */ +#define rseq_unqual_scalar_typeof(x) \ + __typeof__( \ + _Generic((x), \ + char: (char)0, \ + rseq_scalar_type_to_expr(char), \ + rseq_scalar_type_to_expr(short), \ + rseq_scalar_type_to_expr(int), \ + rseq_scalar_type_to_expr(long), \ + rseq_scalar_type_to_expr(long long), \ + default: (x) \ + ) \ + ) +#endif + #endif /* RSEQ_COMPILER_H_ */