Re: [Cocci] linux: special logic in repetitive tests
> Wonder harder. > > If something is (& 3) it is also either (& 2 || & 1) > so why have both below the first test? Would you occasionally prefer to use enumeration values together with switch statements at such source code places? Regards, Markus ___ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci
Re: [Cocci] linux: special logic in repetitive tests
On Tue, 2020-03-31 at 08:28 +0200, Markus Elfring wrote: > > There is a block of if tests against the same variable > > in include/linux/mtd/pfow.h that likely is defective > > I wonder about this interpretation. Wonder harder. If something is (& 3) it is also either (& 2 || & 1) so why have both below the first test? > * How often will this implementation detail really be a “defect”? Moderately likely. > * Where do you stumble on difficulties to express a corresponding source code > search pattern by the means of the semantic patch language? #defines, shifts, masks ___ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci
Re: [Cocci] linux: special logic in repetitive tests
> Wonder harder. > > If something is (& 3) it is also either (& 2 || & 1) > so why have both below the first test? I can interpret the source code example in the way that the number of set bits are checked. I can eventually become concerned around the preferred coding style because of the usage of these constant values. Would you like to check the use of bit fields? >> * Where do you stumble on difficulties to express a corresponding source code >> search pattern by the means of the semantic patch language? > > #defines, shifts, masks You come along the usual development challenges for the safe handling of possible code variations. With which approach would you like to start and perform further source code analysis? Regards, Markus ___ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci
Re: [Cocci] linux: special logic in repetitive tests
> There is a block of if tests against the same variable > in include/linux/mtd/pfow.h that likely is defective I wonder about this interpretation. > Likely the first test should be something like > > if ((prog_status & 0x03) == 0x03) Why would you prefer such a code variant? > Is there a way for cocci to find this style of bitwise logic defect? * Probably, yes. * How often will this implementation detail really be a “defect”? * Where do you stumble on difficulties to express a corresponding source code search pattern by the means of the semantic patch language? Regards, Markus ___ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci
