On Sun, Feb 18, 2018 at 9:47 PM, Eugeniu Rosca <roscaeugeniu@xxxxxxxxx> wrote:
> 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(-)
>
> --
> 2.16.1
>
Whole patchset looks fine to me now:
Reviewed-by: Ulf Magnusson <ulfalizer@xxxxxxxxx>
Cheers,
Ulf
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