On Thu, Mar 27, 2014 at 6:48 AM, Manuel López-Ibáñez <lopeziba...@gmail.com> wrote: > On 27/03/14 09:52, Florian Weimer wrote:> On 03/27/2014 08:44 AM, > Andrew Haley wrote: >> >>> On 03/26/2014 03:05 PM, Daniel Gutson wrote: >>> >>>> assigning a negative literal to an unsigned variable issues no >>>> warning: >>>> >>>> >>>> unsigned int x; >>>> x =- 4; >>>> >>>> This is specially important in typos when -= was intended instead of =- >>>> >>>> Would be acceptable if I add a new warning to handle this, i.e. >>>> -Wnegative-to-unsigned >>>> or alike? >>> >>> Assigning a negative literal to an unsigned variable is well-defined >>> standard C. Is it really appropriate to warn for correct code? >> >> Yes, this warning needs to take whitespace into account. But then, I suppose >> it would be fine. >> > > This is already warned by -Wconversion/-Wsign-conversion since at > least GCC 4.6 (but I think probably since GCC 4.3): > > test.c: In function 'foo': > test.c:4:8: warning: negative integer implicitly converted to unsigned > type [-Wsign-conversion] > x =- 4; > ^
I didn't have such warning in my radar. Good one! > > There are some known bugs in -Wconversion and nobody working on them, > so if you are still interested in helping, I can give you some hints > on where your help will be very welcome. Could you please go ahead and show me the failing cases? I only worked in the backend, but I'd like to take a look to the front-end. There's also all the other commenters of my post regarding the =- and =+ looking-like operators, which should take ws into account. > > Cheers, > > Manuel. -- Daniel F. Gutson Chief Engineering Officer, SPD San Lorenzo 47, 3rd Floor, Office 5 Córdoba, Argentina Phone: +54 351 4217888 / +54 351 4218211 Skype: dgutson
