[bug #45311] makes only one of two dependencies that depend on the same subdir-pattern rule
Follow-up Comment #5, bug #45311 (project make): We'd have to ask Roland or RMS; that behavior was already present when I first started using GNU make, IIRC, and I'm not sure where it originated. I think the idea that you can generate multiple outputs with a single command is a very important capability, but I agree the current implementation (where patterns and explicit targets work in opposite ways, and you can't get the other way) is not ideal. ___ Reply to this item at: http://savannah.gnu.org/bugs/?45311 ___ Message sent via/by Savannah http://savannah.gnu.org/ ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
[bug #45311] makes only one of two dependencies that depend on the same subdir-pattern rule
Follow-up Comment #4, bug #45311 (project make): $@ wasn't the source of my confusion. Though the simplified test case would indeed have worked if $@ expanded to all targets, my actual Makefile wouldn't. What confused me was the different behaviour of multiple-target rules with and without patterns; the former are run once for all targets, the latter once for each target. It seems quite unintuitive to me. Is there a reason for it, other than historical? ___ Reply to this item at: http://savannah.gnu.org/bugs/?45311 ___ Nachricht gesendet von/durch Savannah http://savannah.gnu.org/ ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
[bug #45311] makes only one of two dependencies that depend on the same subdir-pattern rule
URL: http://savannah.gnu.org/bugs/?45311 Summary: makes only one of two dependencies that depend on the same subdir-pattern rule Project: make Submitted by: frank Submitted on: Fr 12 Jun 2015 22:55:52 GMT Severity: 3 - Normal Item Group: Bug Status: None Privacy: Public Assigned to: None Open/Closed: Open Discussion Lock: Any Component Version: 4.1 Operating System: POSIX-Based Fixed Release: None Triage Status: None ___ Details: % cat Makefile all: testdir/a testdir/b %/a %/b:; touch $@ % rm -rf testdir % mkdir testdir % make touch testdir/a % make touch testdir/b The first make only makes a and forgets b. I wondered if my rules are actually right like this, but since the second time make does make b, it seems so to me. It works as expected when I write two separate, but identical, rules for %/a and %/b. ___ Reply to this item at: http://savannah.gnu.org/bugs/?45311 ___ Nachricht gesendet von/durch Savannah http://savannah.gnu.org/ ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
[bug #45311] makes only one of two dependencies that depend on the same subdir-pattern rule
Follow-up Comment #3, bug #45311 (project make): Well, make walks targets one at a time, so there will always be a first target which is determined to be out of date and matches a given pattern rule, causing the recipe to fire. That target is the one that will be set with $@. The rest of the targets are marked as also built. I definitely wouldn't expect that $@ would contain multiple targets but maybe it's just because I'm too close :). Having something that is normally just one file be multiple files is not expected, IMO. In general in pattern rules with multiple targets, $* is more useful than $@. ___ Reply to this item at: http://savannah.gnu.org/bugs/?45311 ___ Message sent via/by Savannah http://savannah.gnu.org/ ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
[bug #45311] makes only one of two dependencies that depend on the same subdir-pattern rule
Update of bug #45311 (project make): Status:None = Not A Bug Open/Closed:Open = Closed ___ Follow-up Comment #1: I may be missing something, but this looks correct to me. A pattern rule with multiple targets is different than an explicit rule with multiple targets: a pattern rule with multiple targets invokes the recipe _one time_ and expects that to build all the targets. See the last paragraph in http://www.gnu.org/software/make/manual/html_node/Pattern-Intro.html As expected, make runs your recipe only one time; it expects that both targets will be created. If there's something I'm misunderstanding please add a comment and I'll reopen the bug. ___ Reply to this item at: http://savannah.gnu.org/bugs/?45311 ___ Message sent via/by Savannah http://savannah.gnu.org/ ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
[bug #45311] makes only one of two dependencies that depend on the same subdir-pattern rule
Follow-up Comment #2, bug #45311 (project make): I think the confusion here has to do with the value of $@. One might reasonably expect, in a multi-target pattern rule, that $@ would be the list of all matching out-of-date targets but in fact, according to the documentation: In a pattern rule that has multiple targets (see Introduction to Pattern Rules), ‘$@’ is the name of whichever target caused the rule’s recipe to be run. Which is a bit unclear wrt the case where neither target exists, but does imply strongly that $@ will refer to just one target. ___ Reply to this item at: http://savannah.gnu.org/bugs/?45311 ___ Message sent via/by Savannah http://savannah.gnu.org/ ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
