On Fri, 22 Mar 2019 at 16:07, Joe Perches <joe@xxxxxxxxxxx> wrote: > > On Fri, 2019-03-22 at 15:29 +0100, Ard Biesheuvel wrote: > > On Fri, 22 Mar 2019 at 13:43, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote: > > > On Thu, Mar 07, 2019 at 04:15:55PM -0800, Joe Perches wrote: > > > > Normal use of IS_ENABLED is with a CONFIG_<SYMBOL> and > > > > there is no -DDEBUG in the Makefile here. > > > > > > > > Replace the IS_ENABLED(DEBUG) with #ifdef DEBUG/#endif > > > > blocks. > > > > > > > > Miscellanea: > > > > > > > > o Move the sahara_state array into the function that uses it. > > > > > > > > Signed-off-by: Joe Perches <joe@xxxxxxxxxxx> > > > > --- > > > > drivers/crypto/sahara.c | 20 +++++++++----------- > > > > 1 file changed, 9 insertions(+), 11 deletions(-) > > > > > > Even if this is correct this is way too ugly. The original code > > > at least compiled everything regardless of macros. Your new code > > > won't detect compile errors in debugging code unless debugging is > > > enabled. > > > > > > > What's wrong with IS_ENABLED(DEBUG) anyway? It may not be 'normal use' > > but it works fine. > > drivers/crypto/sahara.c is the only user in the kernel tree. > So only it's abnormal use. I rather like the concept actually. > > IS_ENABLED is almost exclusively used with CONFIG_<FOO> symbols > and it could be useful to require it to be used with CONFIG_<FOO> > symbols and use some other similar mechanism for DEBUG use. > > Maybe just adding a global #define in kernel.h like > > #define IS_DEBUG_ENABLED IS_ENABLED(DEBUG) > __is_defined(DEBUG) seems to be the most appropriate here. I don't feel strongly about whether we or not should wrap it in another macro. > to isolate this in one place might be better. > > A good thing about using IS_ENABLED or the suggested IS_DEBUG_ENABLED > would be that least gcc 5+ seems to automatically elide the uses of any > unreferenced static const char * arrays like the sahara_state uses here. > Yes, that is kind of the point. If you use #ifdef, the compiler will complain about unused static variables in this case. > (I don't have gcc4 anymore so I couldn't check that version) > > So using 'if (IS_DEBUG_ENABLED)' could simplify some existing code like > the many uses of > > #ifdef DEBUG > ... > #endif > > or equivalent > > My vote would be to use __is_defined(DEBUG) in place, but if others prefer wrapping it in a macro, that is also fine with me.
