From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Desaulniers Subject: Re: [PATCH] IB/mlx4: Avoid implicit enumerated type conversion Date: Thu, 27 Sep 2018 15:42:24 -0700 Message-ID: References: <20180924195716.30848-1-natechancellor@gmail.com> <20180924222737.GA26973@flashbox> <20180925023722.GA32600@ziepe.ca> <20180927010803.GA7640@flashbox> <20180927044826.GC24889@ziepe.ca> <20180927202849.GA11120@flashbox> <20180927222821.GC28301@ziepe.ca> <1538087622.226558.8.camel@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <1538087622.226558.8.camel@acm.org> Sender: linux-kernel-owner@vger.kernel.org To: bvanassche@acm.org Cc: jgg@ziepe.ca, Nathan Chancellor , dledford@redhat.com, linux-rdma@vger.kernel.org, LKML List-Id: linux-rdma@vger.kernel.org On Thu, Sep 27, 2018 at 3:33 PM Bart Van Assche wrote: > > On Thu, 2018-09-27 at 16:28 -0600, Jason Gunthorpe wrote: > > On Thu, Sep 27, 2018 at 01:34:16PM -0700, Nick Desaulniers wrote: > > > > > > Neither ib_qp_create_flags nor mlx4_ib_qp_flags have negative values, is > > > > signedness necessary? > > > > > > enums are by default restricted to the range of ints. > > > > That's not quite right, the compiler sizes the enum to be able to fit > > the largest value contained within, today that is int, but if we added > > 1<<31, then it would become larger. > > Hi Jason, > > Are you perhaps confusing C and C++? For C++, an enumeration whose underlying > type is not fixed, the underlying type is an integral type that can represent > all the enumerator values defined in the enumeration. For C however I think > that enumeration values are restricted to what fits in an int. > > Bart. > To quote the sacred texts (ANSIIISO9899-1990): 6.5.2.2 Enumeration specifiers The expression that defines the value of an enumeration constant shall be an integral constant expression that has a value representable as an int. -- Thanks, ~Nick Desaulniers