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From:   Jiri Olsa <olsajiri@gmail.com>
Date:   Mon, 22 Aug 2022 12:58:49 +0200
To:     roberto.sassu@huaweicloud.com
Cc:     peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
        mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
        namhyung@kernel.org, quentin@isovalent.com,
        linux-perf-users@vger.kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Roberto Sassu <roberto.sassu@huawei.com>
Subject: Re: [PATCH 3/3] tools/build: Display logical OR of a feature flavors
Message-ID: <YwNhabqHEq3PfNM8@krava>
References: <20220818120957.319995-1-roberto.sassu@huaweicloud.com>
 <20220818120957.319995-3-roberto.sassu@huaweicloud.com>
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On Thu, Aug 18, 2022 at 02:09:57PM +0200, roberto.sassu@huaweicloud.com wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
> 
> Sometimes, features are simply different flavors of another feature, to
> properly detect the exact dependencies needed by different Linux
> distributions.
> 
> For example, libbfd has three flavors: libbfd if the distro does not
> require any additional dependency; libbfd-liberty if it requires libiberty;
> libbfd-liberty-z if it requires libiberty and libz.
> 
> It might not be clear to the user whether a feature has been successfully
> detected or not, given that some of its flavors will be set to OFF, others
> to ON.
> 
> Instead, display only the feature main flavor if not in verbose mode
> (VF != 1), and set it to ON if at least one of its flavors has been
> successfully detected (logical OR), OFF otherwise. Omit the other flavors.
> 
> Accomplish that by declaring a FEATURE_GROUP_MEMBERS-<feature main flavor>
> variable, with the list of the other flavors as variable value. For now, do
> it just for libbfd.
> 
> In verbose mode, of if no group is defined for a feature, show the feature
> detection result as before.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> ---
>  tools/build/Makefile.feature | 27 +++++++++++++++++++++++++--
>  1 file changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> index 6c809941ff01..57619f240b56 100644
> --- a/tools/build/Makefile.feature
> +++ b/tools/build/Makefile.feature
> @@ -137,6 +137,12 @@ FEATURE_DISPLAY ?=              \
>           libaio			\
>           libzstd
>  
> +#
> +# Declare group members of a feature to display the logical OR of the detection
> +# result instead of each member result.
> +#
> +FEATURE_GROUP_MEMBERS-libbfd = libbfd-liberty libbfd-liberty-z

nice, I checked and could not find any other 'flavours' instance
like libbfd, but it might happen in future

for the whole patchset:

Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka


> +
>  # Set FEATURE_CHECK_(C|LD)FLAGS-all for all FEATURE_TESTS features.
>  # If in the future we need per-feature checks/flags for features not
>  # mentioned in this list we need to refactor this ;-).
> @@ -179,8 +185,17 @@ endif
>  #
>  feature_print_status = $(eval $(feature_print_status_code))
>  
> +feature_group = $(eval $(feature_gen_group)) $(GROUP)
> +
> +define feature_gen_group
> +  GROUP := $(1)
> +  ifneq ($(feature_verbose),1)
> +    GROUP += $(FEATURE_GROUP_MEMBERS-$(1))
> +  endif
> +endef
> +
>  define feature_print_status_code
> -  ifeq ($(feature-$(1)), 1)
> +  ifneq (,$(filter 1,$(foreach feat,$(call feature_group,$(feat)),$(feature-$(feat)))))
>      MSG = $(shell printf '...%40s: [ \033[32mon\033[m  ]' $(1))
>    else
>      MSG = $(shell printf '...%40s: [ \033[31mOFF\033[m ]' $(1))
> @@ -244,12 +259,20 @@ ifeq ($(VF),1)
>    feature_verbose := 1
>  endif
>  
> +ifneq ($(feature_verbose),1)
> +  #
> +  # Determine the features to omit from the displayed message, as only the
> +  # logical OR of the detection result will be shown.
> +  #
> +  FEATURE_OMIT := $(foreach feat,$(FEATURE_DISPLAY),$(FEATURE_GROUP_MEMBERS-$(feat)))
> +endif
> +
>  feature_display_entries = $(eval $(feature_display_entries_code))
>  define feature_display_entries_code
>    ifeq ($(feature_display),1)
>      $$(info )
>      $$(info Auto-detecting system features:)
> -    $(foreach feat,$(FEATURE_DISPLAY),$(call feature_print_status,$(feat),) $$(info $(MSG)))
> +    $(foreach feat,$(filter-out $(FEATURE_OMIT),$(FEATURE_DISPLAY)),$(call feature_print_status,$(feat),) $$(info $(MSG)))
>    endif
>  
>    ifeq ($(feature_verbose),1)
> -- 
> 2.25.1
>