On 2017-05-19 06:28, Masahiro Yamada wrote:
> This allows to detect -s option without checking GNU Make version.
>
> As commit e36aaea28972 ("kbuild: Fix silent builds with make-4")
> pointed out, GNU Make 4.x changed the way/order it presents the
> command line options into MAKEFLAGS.
>
> In Make 3.8x, 's' is always be the first in a group of short options.
> The group could be prefixed with '-'.
>
> In Make 4.x, 's' is always the last in a group of short options.
>
> As commit e6ac89fabd03 ("kbuild: Correctly deal with make options
> which contain an 's'") addressed, we also need to deal with long
> options that end with 's', like --warn-undefined-variables.
>
> Test cases:
>
> [1] command line input: make --silent
> -> MAKEFLAGS for Make 3.8x: s
> -> MAKEFLAGS for Make 4.x : s
>
> [2] command line input: make -srR
> -> MAKEFLAGS for Make 3.8x: sRr
> -> MAKEFLAGS for Make 4.x : rRs
>
> [3] command line input: make -s -rR --warn-undefined-variables
> -> MAKEFLAGS for Make 3.8x: --warn-undefined-variables -sRr
> -> MAKEFLAGS for Make 4.x : rRs --warn-undefined-variables
>
> We can take care of them, by filtering out long options (--%),
> then matching -s% s% %s patterns.
Good idea, that's a much cleaner way.
Michal
