bmake .OODATE confusion

[Jonathan Perkin <jperkin%mnx.io@localhost>]

With "mktool fetch" I am using different semantics for the do-fetch 
target.  The target still depends on all distfiles, but instead of each 
distfile target being a separate script that performs the download, I 
download all of the targets in the do-fetch target to significantly 
improve performance with parallel downloads.

This has the drawback of always running mktool, regardless of whether 
the dependency targets exist or not.  I'd like for do-fetch to not 
execute its commands if all of the dependencies are up-to-date.

While trying to find a solution for this, I came across .OODATE.  The 
documentation states:

  "The list of sources for this target that were deemed out-of-date.."

This seems like it would be a possible workaround, i.e. only run mktool 
if "${.OODATE}" != "" or whatever.

However, unless I am misunderstanding this description, it doesn't 
appear to work as I would expect.  Given this simple Makefile:

	all: depfile
		@echo OODATE=${.OODATE}
		@echo ALLSRC=${.ALLSRC}

	depfile:
		@echo Creating ${.TARGET}
		@>${.TARGET}

I would assume the first run will create depfile and OODATE and ALLSRC 
to be identical, and then the second run OODATE will be empty (because 
"depfile" is up-to-date) and ALLSRC will continue to list "depfile".  

However:

  $ bmake -V MAKE_VERSION
  20240711

  $ bmake
  Creating depfile
  OODATE=depfile
  ALLSRC=depfile

  $ bmake
  OODATE=depfile
  ALLSRC=depfile

Am I misunderstanding the documentation, should the documentation be 
improved to avoid this misunderstanding, or is this a bug?

--
Jonathan Perkin   -   mnx.io   -   pkgsrc.smartos.org
Open Source Complete Cloud   www.tritondatacenter.com