Re: Cryptic idiom

[Lloyd Parkes <lloyd%must-have-coffee.gen.nz@localhost>]

On 19/12/2025 06:35, Frédéric Fauberteau wrote:
> Hi,
>
> I am not sur to understand this idiom in mk/tools/replace.mk:
>
> ```
> .  elif defined(TOOLS_PLATFORM.${_t_}) && !empty(TOOLS_PLATFORM.${_t_})
> #####
> ##### For each system-supplied tool, break the tool down into a path
> ##### and arguments so that either a symlink or a wrapper will be
> ##### properly created.
> #####
> TOOLS_CREATE+=    ${_t_}
> TOOLS_PATH.${_t_}?= \
>    ${TOOLS_PLATFORM.${_t_}:C/^/_asdf_/1:M_asdf_*:S/^_asdf_//}
> TOOLS_ARGS.${_t_}?= \
>    ${TOOLS_PLATFORM.${_t_}:C/^/_asdf_/1:N_asdf_*}
> .  endif
> ```
>
> Given that TOOLS_PLATFORM.${_t_} is defined and not empty, how could applying ":C/^/_asdf_/1:M_asdf_*:S/^_asdf_//" produce anything other than TOOLS_PLATFORM.${_t_} itself?

It selects the first word in TOOLS_PLATFORM.${_t_} in the case that it 
is a sequence of words.

Ngā mihi, Lloyd