Re: [PATCH v2 1/5] Documentation/Makefile: conditionally include doc.dep
From: Junio C Hamano <hidden>
Date: 2020-12-07 07:45:43
Ramsay Jones [off-list ref] writes:
Notice that, since the 'doc.dep' file does not exist, make takes the time (about 8s) to generate several files in order to create the doc.dep include file. (If an 'include' file is missing, but a target for the said file is present in the Makefile, make will execute that target and, if that file now exists, throw away all its internal data and re-read and re-parse the Makefile). Having spent the time to include the 'doc.dep' file, the 'clean' target immediately deletes those files. In order to eliminate such wasted effort, use the value of the internal $(MAKECMDGOALS) variable to only '-include doc.dep' when the target is not 'clean'. (This drops the time down to 12.364s, on my laptop, giving an improvement of 47.02%).
Nicely explained. It might be worth saying
... the clean target immediately deletes those files. The rules
and definitions of doc.dep however does not affect what 'clean'
target removes otherwise, so we can do without all this.
The last paragraph made me wonder what should happen for 'distclean'
etc., but luckily there is only 'clean' in Documentation/Makefile ;-)
quoted hunk
Signed-off-by: Ramsay Jones <redacted> --- Documentation/Makefile | 2 ++ 1 file changed, 2 insertions(+)diff --git a/Documentation/Makefile b/Documentation/Makefile index 80d1908a44..652d57a1b6 100644 --- a/Documentation/Makefile +++ b/Documentation/Makefile@@ -286,7 +286,9 @@ doc.dep : $(docdep_prereqs) $(wildcard *.txt) $(wildcard config/*.txt) build-doc $(PERL_PATH) ./build-docdep.perl >$@+ $(QUIET_STDERR) && \ mv $@+ $@ +ifneq ($(MAKECMDGOALS),clean) -include doc.dep +endif cmds_txt = cmds-ancillaryinterrogators.txt \ cmds-ancillarymanipulators.txt \