[Buildroot] [RFC 1/3] pkg-utils: introduce a make-based LOWERCASE function
Arnout Vandecappelle
arnout at mind.be
Tue Mar 25 21:47:04 UTC 2014
On 23/03/14 18:43, Thomas Petazzoni wrote:
> Until now, our UPPERCASE function was implemented purely in make for
> performance reasons, but our LOWERCASE function was implemented by
> calling "tr", which was reasonable due to the fact that LOWERCASE was
> rarely used.
>
> An upcoming change is going to make LOWERCASE used quite a bit more,
> so we turn it into a pure make function.
>
> Moreover, we want this LOWERCASE function to turn a "_" into a "-" and
> not a ".", so we slightly adjust the existing FROM and TO lists to
> make this possible. This doesn't change the behavior of the UPPERCASE
> macro because both "-" and "." are converted into "_" by this
> function.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
> package/pkg-utils.mk | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/package/pkg-utils.mk b/package/pkg-utils.mk
> index 91a1981..8c3e534 100644
> --- a/package/pkg-utils.mk
> +++ b/package/pkg-utils.mk
> @@ -13,7 +13,7 @@
> # as this macro is used a lot it matters
> # This works by creating translation character pairs (E.G. a:A b:B)
> # and then looping though all of them running $(subst from,to,text)
> -[FROM] := a b c d e f g h i j k l m n o p q r s t u v w x y z . -
> +[FROM] := a b c d e f g h i j k l m n o p q r s t u v w x y z - .
> [TO] := A B C D E F G H I J K L M N O P Q R S T U V W X Y Z _ _
>
> UPPERCASE = $(strip $(eval __tmp := $1) \
> @@ -23,13 +23,12 @@ UPPERCASE = $(strip $(eval __tmp := $1) \
> $(__tmp)))) \
> $(__tmp))
>
> -# LOWERCASE macro -- transforms its arguments to lowercase
> -# The above non-tr implementation is not needed, because LOWERCASE is not
> -# called very often
> -
> -define LOWERCASE
> -$(shell echo $1 | tr '[:upper:]' '[:lower:]')
> -endef
> +LOWERCASE = $(strip $(eval __tmp := $1) \
> + $(foreach c, $(join $(addsuffix :,$([TO])),$([FROM])), \
> + $(eval __tmp := \
> + $(subst $(word 1,$(subst :, ,$c)),$(word 2,$(subst :, ,$c)),\
> + $(__tmp)))) \
> + $(__tmp))
I get a further 30-40% speedup with the following definition:
define caseconvert-helper
$(1) = $$(strip \
$$(eval __tmp := $$(1))\
$(foreach c, $(2),\
$$(eval __tmp := $$(subst $(word 1,$(subst :, ,$c)),$(word 2,$(subst :, ,$c)),$$(__tmp))))\
$$(__tmp))
endef
$(eval $(call caseconvert-helper,UPPERCASE,$(join $(addsuffix :,$([FROM])),$([TO]))))
$(eval $(call caseconvert-helper,LOWERCASE,$(join $(addsuffix :,$([TO])),$([FROM]))))
(this avoids re-evaluating the foreach in every call).
Regards,
Arnout
>
> #
> # Manipulation of .config files based on the Kconfig
>
--
Arnout Vandecappelle arnout at mind be
Senior Embedded Software Architect +32-16-286500
Essensium/Mind http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
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