[lldb-dev] Interest in enabling -Werror by default

Tue Feb 16 19:19:33 PST 2016

On Tue, Feb 16, 2016 at 12:38 PM, Kamil Rytarowski <n54 at gmx.com> wrote:

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> NetBSD builds with GCC 4.8.2 and it emits few warnings for LLDB.
>
> Before enabling -Werror please first iterate over build logs and help
> to squash them. For example it detects undefined behavior IIRC for a
> Darwin code part.

Interesting.  On Linux, lldb had many warnings, and over time, I've managed
to get mots of them cleaned up.  Right now, there are a couple of
-Wtype-limits warnings and one -Wformat warning.  Is there a build bot that
can be used to monitor what those warnings are?  If there aren't any
buildbots, then this would be of no consequence since we wouldn't turn it
on for user builds.

I wish I had caught what I wrote versus what I was thinking before hitting
send :-(.

>
> On 16.02.2016 20:01, Zachary Turner via lldb-dev wrote:
> > You're talking about doing it on a per-bot basis and not a global
> > policy, but just throwing in that on the MSVC side at least, we're
> > not warning free right now and it's not trivial tog et warning free
> > without disabling some warnings (which I don't want to do either)
> >
> > On Tue, Feb 16, 2016 at 10:31 AM Saleem Abdulrasool via lldb-dev
> > <lldb-dev at lists.llvm.org <mailto:lldb-dev at lists.llvm.org>> wrote:
> >
> > On Tuesday, February 16, 2016, Tamas Berghammer
> > <tberghammer at google.com <mailto:tberghammer at google.com>> wrote:
> >
> > If you want to enable it only on the bots then I think we can
> > decide it on a bot by bot bases. For me the main question is who
> > will be responsible for fixing a warning introduced by a change in
> > llvm or clang causing a build failure because of a warning
> > (especially when the fix is non trivial)?
> >
> >
> > I think that the same policy as LLVM/clang should apply here.  The
> > person making the change would be responsible for ensuring that
> > nothing breaks as a result of their change.  The same situation
> > exists when working on interfaces that effect clang: a fix for a
> > warning introduced by a change in LLVM may be non-trivial in
> > clang.
> >
> > Just to be clear, I'm merely suggesting this as an option.  If it
> > is deemed too burdensome by most of the common committers, we state
> > so and not do this.
> >
> >
> >
> > On Tue, Feb 16, 2016 at 4:31 PM Saleem Abdulrasool
> > <compnerd at compnerd.org> wrote:
> >
> > On Tuesday, February 16, 2016, Tamas Berghammer
> > <tberghammer at google.com> wrote:
> >
> > I would be happy if we can keep lldb warning free but I don't think
> > enabling -Werror is a good idea for 2 reasons: * We are using a lot
> > of different compiler and keeping the codebase warning free on all
> > of them might not be feasible especially for the less used, older
> > gcc versions. * Neither llvm nor clang have -Werror enabled so if
> > we enable it then a clang/llvm change can break our build with a
> > warning when it is hard to justify a revert and a fix might not be
> > trivial.
> >
> >
> > Err, sorry.  I meant by default on the build bots (IIRC, some
> > (many?) of the build bots do build with -Werror for LLVM and
> > clang).  Yes, a new warning in clang could cause issues in LLDB,
> > though the same thing exists for the LLVM/clang dependency.  Since
> > this would be on the build bots, it should get resolved rather
> > quickly.
> >
> > In short term I would prefer to just create a policy saying
> > everybody should write warning free code for lldb (I think it
> > already kind of exists) and we as a community try to ensure it
> > during code review and with fixing the possible things what slip
> > through. In the longer term I would be happy to see -Werror turned
> > on for llvm and clang first and then we can follow up with lldb but
> > making this change will require a lot of discussion and might get
> > some push back.
> >
> > On Tue, Feb 16, 2016 at 6:02 AM Saleem Abdulrasool via lldb-dev
> > <lldb-dev at lists.llvm.org> wrote:
> >
> > Hi,
> >
> > It seems that enabling -Werror by default is within reach for lldb
> > now.  There currently are three warnings that remain with gcc 5.1
> > on Linux, and the build is clean of warnings with clang.
> >
> > There are two instances of type range limitations on comparisons in
> > asserts, and one instance of string formatting which has a GNU
> > incompatibility.
> >
> > Is there any interest in enabling -Werror by default to help keep
> > the build clean going forward?
> >
> > -- Saleem Abdulrasool compnerd (at) compnerd (dot) org
> > _______________________________________________ lldb-dev mailing
> > list lldb-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
> >
> >
> >
> > -- Saleem Abdulrasool compnerd (at) compnerd (dot) org
> >
> >
> >
> > -- Saleem Abdulrasool compnerd (at) compnerd (dot) org
> > _______________________________________________ lldb-dev mailing
> > list lldb-dev at lists.llvm.org <mailto:lldb-dev at lists.llvm.org>
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
> >
> >
> >
> > _______________________________________________ lldb-dev mailing
> > list lldb-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
> >
>
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-- 
Saleem Abdulrasool
compnerd (at) compnerd (dot) org
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