On 08/22, David Laight wrote: > ... > > > That typecheck() is horrid. > > > It may well have caused more bugs due to incorrect casts that > > > it actually detected. > > > > > > I'd suggest the version that just avoids multiple evaluations. > > > Or just error signed v unsigned comparisons. > > > See https://lore.kernel.org/all/b4ce9dad748e489f9314a2dc95615033@xxxxxxxxxxxxxxxx/ > > > for an example patch set. > > > > Interesting, thanks. That is also simpler. > > > > Also, the existing patch is no worse than the open coded code today, > > so even without code to avoid multiple evaluations, I guess it's okay > > to merge. > > > > The coccinelle warnings are arguably false positives, using checks for > > kernel code, but being run against userspace code that has no access > > to those helpers. But fine to silence them. > > You can't use is_constexpr() unless 'sizeof *(void *)' is valid. > And builtin_constant() isn't good enough for builtin_choose_expr(). > > That might be ok for selftests and tools, but not for generaluserspace. > > David > > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK > Registration No: 1397386 (Wales) I tried to use the relaxed version provided in the shared patchset link besides not able to use is_constexpr(), I'm not able to use __UNIQUE_ID() also. It's definded inside include/linux/compiler-gcc.h and it uses another macro __PASTE() which is defined inside include/linux/compiler_types.h. not sure what to do next - bring those macros definitions to able to use the relaxed version. - if the most important point for min/max defines inside selftests is to avoid multiple evaluation is the below version acceptable? /* #define min(x, y) ({ \ typeof(x) _x = (x); \ typeof(y) _y = (y); \ _x < _y ? _x : _y; \ }) #define max(x, y) ({ \ typeof(x) _x = (x); \ typeof(y) _y = (y); \ _x > _y ? _x : _y; \ }) */
