On Thu, Feb 13 2014, Austin Clements <[email protected]> wrote: > Quoth Tomi Ollila on Jan 25 at 12:21 pm: >> So that the target is newer than its prerequisites. >> --- >> emacs/Makefile.local | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/emacs/Makefile.local b/emacs/Makefile.local >> index 42bfbd9..d5d402e 100644 >> --- a/emacs/Makefile.local >> +++ b/emacs/Makefile.local >> @@ -32,8 +32,7 @@ emacs_bytecode = $(emacs_sources:.el=.elc) >> ifeq ($(HAVE_EMACS),1) >> $(dir)/.eldeps: $(dir)/Makefile.local $(dir)/make-deps.el $(emacs_sources) >> $(call quiet,EMACS) --directory emacs -batch -l make-deps.el \ >> - -f batch-make-deps $(emacs_sources) > [email protected] && \ >> - (cmp -s [email protected] $@ || mv [email protected] $@) >> + -f batch-make-deps $(emacs_sources) > [email protected] && mv [email protected] $@ >> -include $(dir)/.eldeps >> endif >> CLEAN+=$(dir)/.eldeps $(dir)/.eldeps.tmp > > Is this just so the rule doesn't get run again on the next make > invocation (unless, of course, a dependent changed)?
Basically yes. I did multiple builds in rapid succession when developing something and this thing confused me quite a lot in the beginning... > Interestingly, if any of the dependents have changed, but in ways that > don't affect .eldeps, this change will make the build more expensive > because it will trigger a make restart after .eldeps is updated. I wondered what was the reason for the recipe you've chosen here, has it something to do with inodes or something ;) (and were going to ask an alternative to touch (or even : > $@) the target... ... but now I understand. E.g. change in notmuch-lib.el will cause *all* .el files to be re-bytecompiled after this change. An alternative to this patch would be adding a message to the rule which informs user to touch .eldeps to avoid re-doing .eldeps if that irritates one :D something like: (cmp -s [email protected] $@ && \ echo "touch $@ to avoid redoing this target" || mv [email protected] $@) Thanks, Tomi _______________________________________________ notmuch mailing list [email protected] http://notmuchmail.org/mailman/listinfo/notmuch
