From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28414 invoked by alias); 13 Oct 2014 15:59:56 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 28402 invoked by uid 89); 13 Oct 2014 15:59:55 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.5 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-pa0-f45.google.com Received: from mail-pa0-f45.google.com (HELO mail-pa0-f45.google.com) (209.85.220.45) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Mon, 13 Oct 2014 15:59:53 +0000 Received: by mail-pa0-f45.google.com with SMTP id rd3so6011755pab.4 for ; Mon, 13 Oct 2014 08:59:52 -0700 (PDT) X-Received: by 10.66.157.73 with SMTP id wk9mr4881504pab.101.1413215992013; Mon, 13 Oct 2014 08:59:52 -0700 (PDT) Received: from ShengShiZhuChengdeMacBook-Pro.local ([223.72.65.118]) by mx.google.com with ESMTPSA id ki1sm11600404pdb.59.2014.10.13.08.59.49 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Oct 2014 08:59:50 -0700 (PDT) Message-ID: <543BF857.9080805@gmail.com> Date: Mon, 13 Oct 2014 15:59:00 -0000 From: Chen Gang User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: Mark Kettenis CC: gdb-patches@sourceware.org, palves@redhat.com Subject: Re: [PATCH v2] gdb/i387-tdep.c: Avoid warning for "-Werror=strict-overflow" References: <543A8208.9060605@gmail.com> <201410131516.s9DFGPh9005236@glazunov.sibelius.xs4all.nl> In-Reply-To: <201410131516.s9DFGPh9005236@glazunov.sibelius.xs4all.nl> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2014-10/txt/msg00319.txt.bz2 On 10/13/14 23:16, Mark Kettenis wrote: >> Date: Sun, 12 Oct 2014 21:28:40 +0800 >> From: Chen Gang >> >> gdb requires "-Werror", and I387_ST0_REGNUM (tdep) is 'variable', then >> compiler can think that I387_ST0_REGNUM (tdep) may be a large number, >> which may cause issue, so report warning. >> >> Need fix this warning, and still keep the code clear enough for readers. >> The related warning under Darwin with gnu built gcc: > > Sorry, I disagree with this approach. I think your compiler is really > being unhelpful here. See if a newer GCC version of the compiler > still triggers that warning. If so, complain to the GCC people. > Excuse me, I do not dare to complain it to gcc members, because for me, the compiler's printing is obviously, and proofs itself is correct. If I ask a quite obvious question to them, I guess, I will be complained. Hmm... But I may have an additional trying: Use original gcc and provide "-Werror=strict-overflow" to see what will happen. - If it will report warning too, I can ask gcc members why integrate "-Wstrict-overflow" to -Wall. - If it will not report warning, it means original gcc also integrate "-Wstrict-overflow" or have no this option. And for me, I prefer to use "#pragma GCC diagnostic ignored ... " for our code. Thanks. >> gcc -g -O2 -I. -I../../binutils-gdb/gdb -I../../binutils-gdb/gdb/common -I../../binutils-gdb/gdb/config -DLOCALEDIR="\"/usr/local/share/locale\"" -DHAVE_CONFIG_H -I../../binutils-gdb/gdb/../include/opcode -I../../binutils-gdb/gdb/../opcodes/.. -I../../binutils-gdb/gdb/../readline/.. -I../bfd -I../../binutils-gdb/gdb/../bfd -I../../binutils-gdb/gdb/../include -I../libdecnumber -I../../binutils-gdb/gdb/../libdecnumber -I../../binutils-gdb/gdb/gnulib/import -Ibuild-gnulib/import -DTUI=1 -D_THREAD_SAFE -I/usr/local/Cellar/guile/2.0.11/include/guile/2.0 -I/usr/local/Cellar/gmp/6.0.0a/include -I/usr/local/Cellar/readline/6.3.5/include -I/usr/local/Cellar/bdw-gc/7.2e/include -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -Wall -Wdeclaration-after-statement -Wpointer-arith -Wpointer-sign -Wno-unused -Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts -Wmi! > ssing-protot >> ypes -Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type -Wold-style-declaration -Wold-style-definition -Wformat-nonliteral -Werror -c -o i387-tdep.o -MT i387-tdep.o -MMD -MP -MF .deps/i387-tdep.Tpo ../../binutils-gdb/gdb/i387-tdep.c >> ../../binutils-gdb/gdb/i387-tdep.c: In function 'i387_supply_fsave': >> ../../binutils-gdb/gdb/i387-tdep.c:447:1: error: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Werror=strict-overflow] >> i387_supply_fsave (struct regcache *regcache, int regnum, const void *fsave) >> ^ >> ../../binutils-gdb/gdb/i387-tdep.c: In function 'i387_collect_fsave': >> ../../binutils-gdb/gdb/i387-tdep.c:502:1: error: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Werror=strict-overflow] >> i387_collect_fsave (const struct regcache *regcache, int regnum, void *fsave) >> ^ >> cc1: all warnings being treated as errors >> >> 2014-10-13 Chen Gang >> >> * i387-tdep.c (i387_supply_fsave): Avoid warning for >> "-Werror=strict-overflow" >> --- >> gdb/i387-tdep.c | 10 ++++++---- >> 1 file changed, 6 insertions(+), 4 deletions(-) >> >> diff --git a/gdb/i387-tdep.c b/gdb/i387-tdep.c >> index d66ac6a..609b5be 100644 >> --- a/gdb/i387-tdep.c >> +++ b/gdb/i387-tdep.c >> @@ -450,11 +450,12 @@ i387_supply_fsave (struct regcache *regcache, int regnum, const void *fsave) >> struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); >> enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); >> const gdb_byte *regs = fsave; >> - int i; >> + int i, end; >> >> gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM); >> >> - for (i = I387_ST0_REGNUM (tdep); i < I387_XMM0_REGNUM (tdep); i++) >> + end = I387_XMM0_REGNUM (tdep); /* -Werror=strict-overflow for (X + c) >= X */ >> + for (i = I387_ST0_REGNUM (tdep); i < end; i++) >> if (regnum == -1 || regnum == i) >> { >> if (fsave == NULL) >> @@ -503,11 +504,12 @@ i387_collect_fsave (const struct regcache *regcache, int regnum, void *fsave) >> { >> struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache)); >> gdb_byte *regs = fsave; >> - int i; >> + int i, end; >> >> gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM); >> >> - for (i = I387_ST0_REGNUM (tdep); i < I387_XMM0_REGNUM (tdep); i++) >> + end = I387_XMM0_REGNUM (tdep); /* -Werror=strict-overflow for (X + c) >= X */ >> + for (i = I387_ST0_REGNUM (tdep); i < end; i++) >> if (regnum == -1 || regnum == i) >> { >> /* Most of the FPU control registers occupy only 16 bits in >> -- >> 1.8.5.2 (Apple Git-48) >> -- Chen Gang Open, share, and attitude like air, water, and life which God blessed