tree 99b2da4a9f542d0be3da2816ae367a7ba323dde9
parent 9d3c75818196802bb5bc3c43bb4a52fb89a83e8c
author Andrew G. Morgan <morgan@kernel.org> 1638640267 -0800
committer Andrew G. Morgan <morgan@kernel.org> 1638641930 -0800

Drop perl from the build requirements.

David Seifert at Gentoo made a request to not require perl for
the libcap build since their distribution wants to build it prior
to building perl and so requiring it requires they maintain some
extra patches.

We previously introduced the need for perl in response to some
apparent incompatibilities between various versions of sed:

https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=9494a1fab59ac0b6e4f0bfc536fa482c6d6490b6

However, it has been 13 years since that time so we're optimistic
those problems are no longer present for anyone and we've also
added a make variable abstraction in case some builder wants to
override their system default 'sed' as make BUILD_SED=... etc.

We've also done something similar with make uses of grep, egrep
and fgrep.

Finally, for make variable naming consistency, we've replaced use
of BUILD_GPERF with USE_GPERF. Since folk may be using BUILD_GPERF
in their package building scripts, we error out if it is set.
The expectation is that people will update their package defs.
(Eventually, we plan to reuse BUILD_GPERF as an alias for 'gperf'.)

Signed-off-by: Andrew G. Morgan <morgan@kernel.org>