On Tue, Sep 27, 2016 at 11:10 AM, Bernd Edlinger <bernd.edlin...@hotmail.de> wrote: > On 09/27/16 16:42, Jason Merrill wrote: >> On Tue, Sep 27, 2016 at 10:28 AM, Bernd Edlinger >> <bernd.edlin...@hotmail.de> wrote: >>> On 09/27/16 16:10, Florian Weimer wrote: >>>> * Bernd Edlinger: >>>> >>>>>> “0 << 0” is used in a similar context, to create a zero constant for a >>>>>> multi-bit subfield of an integer. >>>>>> >>>>>> This example comes from GDB, in bfd/elf64-alpha.c: >>>>>> >>>>>> | insn = INSN_ADDQ | (16 << 21) | (0 << 16) | (0 << 0); >>>>>> >>>>> >>>>> Of course that is not a boolean context, and will not get a warning. >>>>> >>>>> Question is if "if (1 << 0)" is possibly a miss-spelled "if (1 < 0)". >>>>> >>>>> Maybe 1 and 0 come from macro expansion.... >>>> >>>> But what's the intent of treating 1 << 0 and 0 << 0 differently in the >>>> patch, then? >>> >>> I am not sure if it was a good idea. >>> >>> I saw, we had code of the form >>> bool flag = 1 << 2; >>> >>> another value LOOKUP_PROTECT is 1 << 0, and >>> bool flag = 1 << 0; >>> >>> would at least not overflow the allowed value range of a boolean. >> >> Assigning a bit mask to a bool variable is still probably not what was >> intended, even if it doesn't change the value. > > That works for me too. > I can simply remove that exception.
Sounds good. Jason
