From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30134 invoked by alias); 13 Oct 2014 15:16:38 -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 30124 invoked by uid 89); 13 Oct 2014 15:16:37 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: glazunov.sibelius.xs4all.nl Received: from sibelius.xs4all.nl (HELO glazunov.sibelius.xs4all.nl) (83.163.83.176) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 13 Oct 2014 15:16:35 +0000 Received: from glazunov.sibelius.xs4all.nl (kettenis@localhost [127.0.0.1]) by glazunov.sibelius.xs4all.nl (8.14.5/8.14.3) with ESMTP id s9DFGQf3029736; Mon, 13 Oct 2014 17:16:26 +0200 (CEST) Received: (from kettenis@localhost) by glazunov.sibelius.xs4all.nl (8.14.5/8.14.3/Submit) id s9DFGPh9005236; Mon, 13 Oct 2014 17:16:25 +0200 (CEST) Date: Mon, 13 Oct 2014 15:16:00 -0000 Message-Id: <201410131516.s9DFGPh9005236@glazunov.sibelius.xs4all.nl> From: Mark Kettenis To: gang.chen.5i5j@gmail.com CC: gdb-patches@sourceware.org, palves@redhat.com, mark.kettenis@xs4all.nl In-reply-to: <543A8208.9060605@gmail.com> (message from Chen Gang on Sun, 12 Oct 2014 21:28:40 +0800) Subject: Re: [PATCH v2] gdb/i387-tdep.c: Avoid warning for "-Werror=strict-overflow" References: <543A8208.9060605@gmail.com> X-SW-Source: 2014-10/txt/msg00318.txt.bz2 > 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. > 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) >