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. Bernd.
