On Mon, Mar 22, 2021 at 01:11:49PM +0100, Ævar Arnfjörð Bjarmason wrote: > Extend the SPATCH_BATCH_SIZE facility added in > 960154b9c17 (coccicheck: optionally batch spatch invocations, > 2019-05-06) and bcb4edf7af7 (coccicheck: make batch size of 0 mean > "unlimited", 2019-05-08) to allow for both setting > SPATCH_BATCH_SIZE=N, and also to have a more advanced SPATCH_XARGS > argument. > > The reason to replace the "$$limit" is that now you actually see under > V=1 what argument your program will get invoked with. > > The reason for the "9999" limit is that if you e.g. try to define an > "$(XARGS)" which is conditionally an empty string or not depending on > this setting then e.g.: > > echo $(FILES) | $(XARGS) $(XARGS_FLAGS) $(SPATCH) > > Over multiple lines with "\" will error out. I think just setting it > to "xargs -n 9999" as a trivial workaround is the best solution here. I don't understand this 9999 comment. The original was sometimes setting $limit to the empty string, and then doing: xargs $limit How is that any different than setting SPATCH_XARGS to just "xargs" for the unlimited case? > +# For the 'coccicheck' target; SPATCH_XARGS can be used to manually > +# tweak the xargs invocation. By default we invoke "xargs -n 1", and > +# "xargs -n 9999" under SPATCH_BATCH_SIZE=0. > +# > +# Setting SPATCH_XARGS overrides SPATCH_BATCH_SIZE. To get concurrency > +# when targeting a single contrib/coccinelle/%.patch use e.g. "-P" if > +# your xargs(1) supports it: > +# > +# make contrib/coccinelle/strbuf.cocci.patch SPATCH_XARGS="xargs -P 8 -n 8" > +# > +# Or a combination -jN and "xargs -P": > +# > +# make -j4 coccicheck SPATCH_XARGS="xargs -P 2 -n 8" As I mentioned in the last round, using "-P" is racy. I'm not sure if it's something we should be recommending to people. -Peff
