Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757265AbbBEKZX (ORCPT ); Thu, 5 Feb 2015 05:25:23 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:5510 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753664AbbBEKZS convert rfc822-to-8bit (ORCPT ); Thu, 5 Feb 2015 05:25:18 -0500 From: Toma Tabacu To: "Maciej W. Rozycki" , Daniel Sanders CC: Ralf Baechle , Paul Burton , Paul Bolle , "Steven J. Hill" , Manuel Lauss , Jim Quinlan , "linux-mips@linux-mips.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH 5/5] MIPS: LLVMLinux: Silence unicode warnings when preprocessing assembly. Thread-Topic: [PATCH 5/5] MIPS: LLVMLinux: Silence unicode warnings when preprocessing assembly. Thread-Index: AQHQP7ajKQVJ2AEG9063KpjdfAGJ6ZzgTWsAgAGO+TA= Date: Thu, 5 Feb 2015 10:25:14 +0000 Message-ID: References: <1422970639-7922-1-git-send-email-daniel.sanders@imgtec.com> <1422970639-7922-6-git-send-email-daniel.sanders@imgtec.com> In-Reply-To: Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [192.168.14.150] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1787 Lines: 35 On Wed, 4 Feb 2015, Maciej W. Rozycki wrote: > 2. It considers these character pairs to be unicode escapes in the first > place given that they do not follow the syntax required for such > escapes, that is `\unnnn', where `n' are hex digits. > It doesn't actually treat them as unicode escapes, but it still warns the user, in case they were meant to be unicode escapes. Here's the warning message: arch/mips/include/asm/asmmacro.h:197:51: warning: \u used with no following hex digits; treating as '\' followed by identifier [-Wunicode] .word 0x41000000 | (\rt << 16) | (\rd << 11) | (\u << 5) | (\sel) ^ I'll add it to the summary in v2. > Of course it may be reasonable for us to work this bug around as we've > been doing for years with GCC, but has the issue been reported back to > clang maintainers? What was their response? > It hasn't been reported, but I don't think they would agree with removing unicode escape sequences from the assembler-with-cpp mode because it is currently being used for other languages as well, not just assembly. One such language is Haskell (ghc, to be more specific), for which the clang developers had to actually stop the preprocessor from enforcing the C universal character name restrictions in assembler-with-cpp mode, which suggests that ghc wants the preprocessor to check for unicode escape sequences. At the moment, we can either disable -Wunicode for asmmacro.h or refrain from using '\u' as an identifier. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/