On Sun, 2019-06-09 at 17:13 -0400, David A. Wheeler wrote: > I propose a new special target .MUSTCREATE. > Its prerequisites would list the targets that would fail in error > if the target rule is run and it fails to create the target. > If there's nothing on the list, then all non-.PHONY targets will > fail in error if the rule runs without creating its target.
I understand the goal, but I'm not sure about this implementation. For one thing, I'm not sure I see the utility in having a list of targets after .MUSTCREATE... surely this option is there for ensuring targets are written properly. It seems not-so-useful as a validation if you have to add a new target as a prerequisite to pseudo-target before it will be checked. So I suggest that this mode of listing explicit targets is not something anyone would really use. Having this pseudo target with no prerequisites enable a mode where all targets are either PHONY or checked seems like something more people would find useful (as you yourself would use it). My main concern with this is that I'm not sure it's so black-and-white out there in "the real world", that every rule will either be PHONY or create a target. What about, for example, FORCE-style rules for portability with make instances that don't support PHONY? Or, how about auto-dependency tracking implementations that have empty rules? Perhaps an adjustment to the definition, which is that "if make invokes a command and the target is not created" would help, so that empty recipes aren't considered. This still doesn't help the FORCE trick. The problem with your suggestion is that if you have even one rule that, legitimately, doesn't create the target then this entire feature is useless to you: enabling it causes your build to fail. Here's an alternative: A pseudo-target .WONTCREATE: If that target exists in the makefile then the target existence checking is enabled, as follows: - Any PHONY rule is not considered - After any target is built that actually invoked at least one command, the existence of the target make expected is checked. If it does exist, then no error is given. - If the target does NOT exist, then the target is checked against the prerequisites of .WONTCREATE. If the target is a prerequisite of .WONTCREATE, then no error is given. - Else make generates an error as the recipe did not create the target. If the target doesn't exist in the makefile then make behaves as before. _______________________________________________ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
