Andres Freund <andres@anarazel.de> writes:
> I'm not quite sure what the proper behaviour is when doing an out-of-tree
> build with meson (all builds are out-of-tree), with a pre-existing flex /
> bison output in the source tree that is out of date.
Definitely sounds like a gotcha.
On the one hand, there's been some discussion already of removing all
derived files from tarballs and just insisting that users provide all
needed tools when building from source. If we did that, it could be
sufficient for the meson build to check that no such files are present
in the source tree. (Checking a couple of them would be enough, likely.)
On the other hand, I'm not sure that I want such a change to be forced
by a toolchain change. It definitely seems a bit contrary to the plan
we'd formed of allowing meson and make-based builds to coexist for
a few years, because we'd be breaking at least some make-based build
processes.
Could we have the meson build check that, say, if gram.c exists it
is newer than gram.y? Or get it to ignore an in-tree gram.c?
regards, tom lane