On Wed, Jul 06, 2016 at 07:37:45AM +0200, Christian Ehrhardt wrote: > *updates in v3* > - replace tac with sed '1!G;h;$!d' to avoid build time dependency > > *updates in v2* > - move to .config target > - fix usage order of tac > - simplify inner section by only using awk (instead of awk+loop+bash+sed) > > Due to the hierarchy and the demand to keep the base config showing all > options, some config keys end up multiple times in the .config file. > > Due to the way the actual config is sourced only the last entry is > important. That can confuse people changing values in .config which > are then ignored. > > 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 at canonical.com> > --- > mk/rte.sdkconfig.mk | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/mk/rte.sdkconfig.mk b/mk/rte.sdkconfig.mk > index a3acfe6..d031bf4 100644 > --- a/mk/rte.sdkconfig.mk > +++ b/mk/rte.sdkconfig.mk > @@ -79,11 +79,17 @@ $(RTE_OUTPUT): > ifdef NODOTCONF > $(RTE_OUTPUT)/.config: ; > else > +# Generate config from template, if there are duplicates keep only the last > $(RTE_OUTPUT)/.config: $(RTE_CONFIG_TEMPLATE) FORCE | $(RTE_OUTPUT) > $(Q)if [ "$(RTE_CONFIG_TEMPLATE)" != "" -a -f "$(RTE_CONFIG_TEMPLATE)" > ]; then \ > $(CPP) -undef -P -x assembler-with-cpp \ > -ffreestanding \ > -o $(RTE_OUTPUT)/.config_tmp $(RTE_CONFIG_TEMPLATE) ; \ > + sed '1!G;h;$$!d' $(RTE_OUTPUT)/.config_tmp > > $(RTE_OUTPUT)/.config_tmp_reverse ; \ > + awk --field-separator '=' '!/^#/ {if (!seen[$$1]) {print > ($$0)}; seen[$$1]=1;} \ > + /^#/ {print($$0)}' $(RTE_OUTPUT)/.config_tmp_reverse \ > + | sed '1!G;h;$$!d' > $(RTE_OUTPUT)/.config_tmp ; \ > + rm $(RTE_OUTPUT)/.config_tmp_reverse ; \ > if ! cmp -s $(RTE_OUTPUT)/.config_tmp $(RTE_OUTPUT)/.config; > then \ > cp $(RTE_OUTPUT)/.config_tmp $(RTE_OUTPUT)/.config ; \ > cp $(RTE_OUTPUT)/.config_tmp $(RTE_OUTPUT)/.config.orig > ; \ > --
Given the length and complexity of the work being done here, using some pretty fancy sed and awk features, I feel that the comment at the top should be expanded to actually explain what is being done and how. I would also include in that explanation how sed is being used to reverse a file. Personally, I would have preferred to keep the dependency on tac for a readability perspective. /Bruce