On Fri, May 3, 2019 at 2:48 PM Kaz Kylheku (gmake) <729-670-0...@kylheku.com> wrote: > Let's try it in a project of mine: > > ~/txr$ make --warn-undefined-variables --silent --dry-run clean 2>&1 > > /dev/null > Makefile:32: warning: undefined variable `CFLAGS' > Makefile:33: warning: undefined variable `EXTRA_FLAGS' > Makefile:37: warning: undefined variable `LDFLAGS' > Makefile:38: warning: undefined variable `EXTRA_LDFLAGS' > > Good. These should be undefined; if the user sets these, we use them. > Glad to see there are no others. :)
We had this sort of issue initially with "legitimate" undefined variables. We added e.g. "CFLAGS ?=#" or "ifdef <blah>" blocks, which eliminated them and allowed us to fail the build if others were introduced. My experience is that if the build doesn't fail warnings tend to be overlooked... One other thing to keep in mind (I'm sure you know this, but for others reading along at home): you might need to be careful about which targets you give. In complex makefiles specifying different targets may change which variables are defined/used, which is why in our code it specified several targets, not just "clean". Cheers, Duane. _______________________________________________ Help-make mailing list Help-make@gnu.org https://lists.gnu.org/mailman/listinfo/help-make
