Re: [dpdk-dev] [RFC] mk: filter duplicate configuration entries

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 6/28/2016 5:38 PM, Christian Ehrhardt wrote:
> On Tue, Jun 28, 2016 at 6:11 PM, Ferruh Yigit <ferruh.yigit@intel.com
> <mailto:ferruh.yigit@intel.com>> wrote:
> 
>     On 6/13/2016 4:10 PM, Christian Ehrhardt wrote:
>     > Due to the hierarchy and the demand to keep the base config shoing all
>     > options some options end up multiple times in the .config file.
>     >
>     > A suggested solution was to filter for duplicates at the end of the
>     > actual config step which is implemented here.
>     >
>     > Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com
>     <mailto:christian.ehrhardt@canonical.com>>
>     > ---
>     >  mk/rte.sdkconfig.mk <http://rte.sdkconfig.mk> | 5 +++++
>     >  1 file changed, 5 insertions(+)
>     >
>     > diff --git a/mk/rte.sdkconfig.mk <http://rte.sdkconfig.mk> b/mk/rte.sdkconfig.mk
>     <http://rte.sdkconfig.mk>
>     > index a3acfe6..734aa06 100644
>     > --- a/mk/rte.sdkconfig.mk <http://rte.sdkconfig.mk>
>     > +++ b/mk/rte.sdkconfig.mk <http://rte.sdkconfig.mk>
>     > @@ -70,6 +70,11 @@ config: notemplate
>     >  else
>     >  config: $(RTE_OUTPUT)/include/rte_config.h $(RTE_OUTPUT)/Makefile
>     Not sure if this should go under this rule, or "$(RTE_OUTPUT)/.config:"
>     and should work with ".config_tmp".
> 
>     >       $(Q)$(MAKE) depdirs
>     > +     tac $(RTE_OUTPUT)/.config | awk --field-separator '=' '!/^#/ {print $$1}' | while read config; do \
>     Why reversing file since already checking all lines one by one in
>     original file?
> 
> 
> Hi,
> every other comment is ok I'll rebase and resubmit once I find some time
> again.
> But for this (tac) the reason is simple - to keep behaviour.
> Currently the last one wins.

Correct, but if I am not missing something, reversing doesn't help to this,
how lines deleted taking care of this:
sed -i "0,/$${config}/{//d}" $(RTE_OUTPUT)/.config;

sed works on original file, and deletes first occurrence, independent
from lines from bottom to up, or up to bottom fed into it.

> So if you have
> CONFIG_A=n
> CONFIG_A=y
> 
> Essentially you have 
> CONFIG_A=y
> 
> By the tac and keeping the first occurrence we maintain behavior.
> It is interestingly hard to "keep the last occurrence" without such
> tricks, but I'm open to suggestions.
>  
> 
>     And instead of checking each line, it is possible to get list of
>     duplicates via "sort | uniq -d".
> 
>  
> That would fail for the reasons outlined above.
> 
>     Although less important, file comments also tripled in final .config.
> 
>     > +             if [ $$(grep "^$${config}=" $(RTE_OUTPUT)/.config | wc -l) -gt 1 ]; then \
>     "grep -c" can be used instead of "grep | wc -l"
> 
>     > +                     sed -i "0,/$${config}/{//d}"
>     $(RTE_OUTPUT)/.config; \
>     > +             fi; \
>     > +     done
>     >       @echo "Configuration done"
>     >  endif
>     >
>     >
> 
>