This series makes the "coccicheck" rule incremental by only re-running "spatch" for those file/rule combinations that changed. The result is that e.g. running "make coccicheck" followed by a: make -W grep.c coccicheck Will take around 2s instead of a *lot* longer. The 3/5 change has all the details about this, and why it's safe. Furthermore we'll properly handle re-building if any of the required headers change (e.g. column.h). I had a previous stab at trying to make "coccicheck" faster a while ago in [1], but that was fatally flawed because it would break in cases where grep.c e.g. dependen on a header that changed. This series doesn't suffer from that issue, because we piggy-back on the corresponding .depend/* files to extract dependency info. This does mean that the incremental speed-ups depend on COMPUTE_HEADER_DEPENDENCIES=yes (which is the case with "gcc" and "clang" by default). I've been running with this series locally for a while. I think it should fully solve the lamentations about the coccicheck being too slow (e.g. in [2]), particularly when paired with the new "spatchcache" helper added in 5/5. Even without that helper running "make coccicheck" e.g. after applying a patch series now becomes viable, provided the patches don't modify one of the "rebuild everything" files we have (such as cache.h and git-compat-util.h). 1. https://lore.kernel.org/git/20210302205103.12230-1-avarab@xxxxxxxxx/ 2. https://lore.kernel.org/git/xmqqh7249b8d.fsf@gitster.g/ Ævar Arnfjörð Bjarmason (5): Makefile: add ability to TAB-complete cocci *.patch rules Makefile: have "coccicheck" re-run if flags change cocci: make "coccicheck" rule incremental cocci: make incremental compilation even faster spatchcache: add a ccache-alike for "spatch" .gitignore | 1 + Makefile | 114 +++++++-- contrib/coccinelle/spatchcache | 217 ++++++++++++++++++ .../coccinelle/the_repository.pending.cocci | 1 - shared.mak | 4 +- 5 files changed, 310 insertions(+), 27 deletions(-) create mode 100755 contrib/coccinelle/spatchcache -- 2.37.2.1279.g64dec4e13cf
