From patchwork Fri Feb 23 17:41:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Myers X-Patchwork-Id: 26039 Received: (qmail 122746 invoked by alias); 23 Feb 2018 17:42:06 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 122357 invoked by uid 89); 23 Feb 2018 17:42:05 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-24.5 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_PASS, URIBL_RED autolearn=ham version=3.3.2 spammy= X-HELO: relay1.mentorg.com Date: Fri, 23 Feb 2018 17:41:57 +0000 From: Joseph Myers To: Subject: Fix another -Os strcoll build issue Message-ID: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 X-ClientProxiedBy: svr-ies-mbx-02.mgc.mentorg.com (139.181.222.2) To SVR-IES-MBX-03.mgc.mentorg.com (139.181.222.3) While there are now clean -Os build and test results on x86_64 (given my patch , pending review), testing with -Os with build-many-glibcs.py shows the build is still failing with -Os everywhere except for x86_64, x86 and s390x. There are a variety of different build failures, but the most common seem to be in strcoll / wcscoll, similar to existing such cases where DIAG_* are used to disable -Wmaybe-uninitialized. There are various different failures even within those functions. This patch fixes one particular case that seems quite common, where the warning appears at the declarations of seq1 and seq2. Tested with build-many-glibcs.py that this fixes the -Os build for aarch64-linux-gnu with GCC 7. 2018-02-23 Joseph Myers * string/strcoll_l.c: Include . (STRCOLL): Ignore -Wmaybe-uninitialized for -Os around declarations of seq1 and seq2. Reviewed-by: Adhemerval Zanella diff --git a/string/strcoll_l.c b/string/strcoll_l.c index 4a63c56..c001ff4 100644 --- a/string/strcoll_l.c +++ b/string/strcoll_l.c @@ -24,6 +24,7 @@ #include #include #include +#include #ifndef STRING_TYPE # define STRING_TYPE char @@ -291,7 +292,17 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2, locale_t l) int result = 0, rule = 0; + /* With GCC 7 when compiling with -Os the compiler warns that + seq1.back_us and seq2.back_us might be used uninitialized. + Sometimes this warning appears at locations in locale/weightwc.h + where the actual use is, but on architectures other than x86_64, + x86 and s390x, a warning appears at the definitions of seq1 and + seq2. This uninitialized use is impossible for the same reason + as described in comments in locale/weightwc.h. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_Os_NEEDS_COMMENT (7, "-Wmaybe-uninitialized"); coll_seq seq1, seq2; + DIAG_POP_NEEDS_COMMENT; seq1.len = 0; seq1.idxmax = 0; seq1.rule = 0;