2018-02-20 17:13 GMT+09:00 Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>:
> 2018-02-19 5:47 GMT+09:00 Eugeniu Rosca <roscaeugeniu@xxxxxxxxx>:
>> From: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx>
>>
>> Hello Masahiro, Ulf, Petr and all,
>>
>> Here are a few words about the motivation behind this patch series.
>>
>> First, the reason I got in touch with Kconfig is to optimize the
>> configuration of automotive kernels, as well as to align the kernel
>> configuration across a number of platforms. In the context of kernel
>> optimization, one of the primary goals is to filter out any features
>> that are not mentioned in the platform requirements.
>>
>> Surprisingly or not, disabling a CONFIG option (which is assumed to
>> be unneeded) may be not so trivial. Especially it is not trivial, when
>> this CONFIG option is selected by a dozen of other configs. Before the
>> moment commit 1ccb27143360 ("kconfig: make "Selected by:" and
>> "Implied by:" readable") was submitted by Petr and eventually popped
>> up in v4.16-rc1, it was an absolute pain to break down the "Selected by"
>> reverse dependency expression in order to identify all those configs
>> which select (IOW *do not allow disabling*) a certain feature (assumed
>> to be not needed).
>>
>> This patch series tries to make one step further and puts at users'
>> fingertips the revdep top level OR sub-expressions grouped/clustered by
>> the tristate value they evaluate to. This should allow the users to
>> directly concentrate on and tackle the active reverse dependencies,
>> which imho are the only ones that matter for a given ARCH and for a
>> given defconfig (nevertheless we still print all of them).
>>
>> Changes v3->v4 (fixed review findings from Ulf):
>> - Remove redundant default cases in switch constructs.
>> - Remove gettext _() tokens in str_append() calls.
>> - Aggregate code repetitions in expr_print_revdep().
>>
>> Changes v2->v3:
>> - Switch from reverse dependencies prefixed by their tristate value to
>> reverse dependencies grouped by the tristate value they evaluate to.
>> - Skip printing "{Selected,Implied} by [y|m|n]:" if there are no top
>> level OR tokens/sub-expressions that evaluate to y|m|n (suggested
>> by Petr).
>> - Use [1] as template for updating the interface/prototype of
>> __expr_print() (suggested by Ulf).
>>
>> Changes v1->v2:
>> - Don't skip the =n reverse dependency OR tokens, since some users might
>> still need this information (suggested by Ulf).
>> - Instead of using "Selected by" for active tokens only, use it for all
>> OR tokens, but specify the tristate value of each token as prefix
>> (suggested by Masahiro).
>>
>> [1] https://marc.info/?l=linux-kbuild&m=151777006005199&w=4
>>
>> Eugeniu Rosca (3):
>> kconfig: Print reverse dependencies on new line consistently
>> kconfig: Prepare for printing reverse dependencies in groups
>> kconfig: Print reverse dependencies in groups
>>
>> scripts/kconfig/expr.c | 102 +++++++++++++++++++++++++++++++++++++-------
>> scripts/kconfig/expr.h | 11 ++++-
>> scripts/kconfig/lkc_proto.h | 1 +
>> scripts/kconfig/menu.c | 37 +++++++++++-----
>> 4 files changed, 124 insertions(+), 27 deletions(-)
>>
>
>
> I do not like this implementation.
> The code is super ugly, the diff-stat is too much than needed.
>
> Please rewrite the code within 20 lines.
>
For a hint, I cleaned up the code base.
https://patchwork.kernel.org/patch/10229545/
which should be equivalent to yours:
https://patchwork.kernel.org/patch/10226951/
No 'enum print_type', please.
--
Best Regards
Masahiro Yamada
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