Re: [PATCH v2 00/20] Introduce `USE_THE_REPOSITORY_VARIABLE` macro

Patrick Steinhardt [off-list ref] writes:

quoted

quoted

But that does beg the question - why is repository.c not
defining the USE_THE_REPOSITORY_VARIABLE?

I think the goal of the series is to eventually get to the point
where nobody uses the_repository variable.  If repository.c, which
consists of a set of service routines that work on a repository
instance, defined it, showing willingness to implicitly rely on
the_repository through things like get_oid_hex() (which would rely
on the_repository->hash_algo), that would go the opposite direction,
so everything, other than the definition of the_repository variable
itself that allows other files that still do rely implicitly on the
variable to link with it, in repository.c would actively want to
refuse to use services only available to those who define USE_THE_*
macro.

Exactly, that's why it doesn't declare `USE_THE_REPOSITORY_VARIABLE`.
The macro doesn't only guard use of `the_repository`, but does also
guards other functions that implicitly relies on it, and we do not want
to use these in "repository.c". So even though the added `extern`
declaration is somewhat ugly, I think it is preferable over defining the
macro.

Slightly off-topic, but in retrospect, the approach of marking "this
file is done" taken by the very initial version of the "no more
implicit access to the_index" series may have been easier to grok
easier to grok for reviewers casually looking at it from the
sideline, than marking "this file still needs work".  When we
gradually deprecated the convenience API that implicitly access
the_index instance, we marked with NO_THE_INDEX_COMPATIBILITY_MACROS
the files that no longer require it (in other words, we are done
with the file wrt the transition).  We later flipped the polarity
and gave USE_THE_INDEX_COMPATIBILITY_MACROS to those that are not
marked with NO_THE_INDEX_COMPATIBILITY_MACROS as we progressed and
the source files that still used the convenience API has become
minorities.

Anyway, I think now people understood what this series aims to
achieve and how it does so, hopefully.

Thanks.