From: Arnd Bergmann <arnd@arndb.de>
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Andre Przywara <andre.przywara@arm.com>,
LAKML <linux-arm-kernel@lists.infradead.org>,
Tony Breeds <tony@bakeyournoodle.com>,
Guenter Roeck <linux@roeck-us.net>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: Updating kernel.org cross compilers?
Date: Wed, 10 May 2017 09:58:13 +0200 [thread overview]
Message-ID: <CAK8P3a38bCS2rSwtQzYROfVBQ549akQZKPUJhcwDrWPN4NA1+w@mail.gmail.com> (raw)
In-Reply-To: <20170509221843.GZ19687@gate.crashing.org>
On Wed, May 10, 2017 at 12:18 AM, Segher Boessenkool
<segher@kernel.crashing.org> wrote:
> On Tue, May 09, 2017 at 03:59:27PM +0100, Andre Przywara wrote:
>> >> I was able to build (bare-metal) toolchains for
>> >> all architectures except arc, m68k, tilegx and tilepro.
>> >
>> > arc needs a more recent GCC; the other probably as well. GCC 7 should
>> > be out very soon, you probably want to wait for that :-)
>>
>> Well, GCC 7 indeed builds better, but then again is a very new compiler.
>> For instance in the moment it spits a lot of warnings when compiling the
>> kernel (mostly due to some *printf analysis). It's not hard to fix, but
>> this will take a while to trickle in and it's questionable whether this
>> will be backported everywhere.
>> So in addition to GCC 7.1 I'd like to have at least GCC 6.3 around,
>> which builds kernels without warnings today.
>
> If you don't want warnings, turn off the warnings or just don't look at
> them... or fix the problems? Many of the new warnings point out actual
> problems.
>
> Many of those sprintf problems in the kernel have already been fixed.
I've been using gcc-7.0 for a long time and fixed a lot of bugs it found,
along with more harmless warnings, but I had disabled a couple of
warning options when I first installed gcc-7 and ended up ignoring
those.
The exact set of additional options I used is:
-Wimplicit-fallthrough=0 -Wno-duplicate-decl-specifier
-Wno-int-in-bool-context -Wno-bool-operation -Wno-format-truncation
-Wno-format-overflow
there were a couple of others that I sent kernel fixes for instead.
I should probably revisit that list and for each of them either
only enable it with "make W=1" or fix all known warnings.
In the long run, I'd actually hope to fix all W=1 warnings too
and enable them by default.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: Updating kernel.org cross compilers?
Date: Wed, 10 May 2017 09:58:13 +0200 [thread overview]
Message-ID: <CAK8P3a38bCS2rSwtQzYROfVBQ549akQZKPUJhcwDrWPN4NA1+w@mail.gmail.com> (raw)
In-Reply-To: <20170509221843.GZ19687@gate.crashing.org>
On Wed, May 10, 2017 at 12:18 AM, Segher Boessenkool
<segher@kernel.crashing.org> wrote:
> On Tue, May 09, 2017 at 03:59:27PM +0100, Andre Przywara wrote:
>> >> I was able to build (bare-metal) toolchains for
>> >> all architectures except arc, m68k, tilegx and tilepro.
>> >
>> > arc needs a more recent GCC; the other probably as well. GCC 7 should
>> > be out very soon, you probably want to wait for that :-)
>>
>> Well, GCC 7 indeed builds better, but then again is a very new compiler.
>> For instance in the moment it spits a lot of warnings when compiling the
>> kernel (mostly due to some *printf analysis). It's not hard to fix, but
>> this will take a while to trickle in and it's questionable whether this
>> will be backported everywhere.
>> So in addition to GCC 7.1 I'd like to have at least GCC 6.3 around,
>> which builds kernels without warnings today.
>
> If you don't want warnings, turn off the warnings or just don't look at
> them... or fix the problems? Many of the new warnings point out actual
> problems.
>
> Many of those sprintf problems in the kernel have already been fixed.
I've been using gcc-7.0 for a long time and fixed a lot of bugs it found,
along with more harmless warnings, but I had disabled a couple of
warning options when I first installed gcc-7 and ended up ignoring
those.
The exact set of additional options I used is:
-Wimplicit-fallthrough=0 -Wno-duplicate-decl-specifier
-Wno-int-in-bool-context -Wno-bool-operation -Wno-format-truncation
-Wno-format-overflow
there were a couple of others that I sent kernel fixes for instead.
I should probably revisit that list and for each of them either
only enable it with "make W=1" or fix all known warnings.
In the long run, I'd actually hope to fix all W=1 warnings too
and enable them by default.
Arnd
next prev parent reply other threads:[~2017-05-10 7:58 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-26 14:14 Updating kernel.org cross compilers? Andre Przywara
2017-04-26 14:14 ` Andre Przywara
2017-04-30 3:37 ` Guenter Roeck
2017-04-30 3:37 ` Guenter Roeck
2017-04-30 5:29 ` Segher Boessenkool
2017-04-30 5:29 ` Segher Boessenkool
2017-05-09 14:59 ` Andre Przywara
2017-05-09 14:59 ` Andre Przywara
2017-05-09 16:26 ` Guenter Roeck
2017-05-09 16:26 ` Guenter Roeck
2017-05-09 22:18 ` Segher Boessenkool
2017-05-09 22:18 ` Segher Boessenkool
2017-05-10 7:58 ` Arnd Bergmann [this message]
2017-05-10 7:58 ` Arnd Bergmann
2017-05-10 13:40 ` Segher Boessenkool
2017-05-10 13:40 ` Segher Boessenkool
2017-05-10 19:32 ` Arnd Bergmann
2017-05-10 19:32 ` Arnd Bergmann
2017-05-23 18:15 ` Chris Metcalf
2017-05-23 18:15 ` Chris Metcalf
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