On Thu, 2021-07-01 at 14:14 -0400, Tom Lane wrote:
> Peter Eisentraut <peter.eisentraut@enterprisedb.com> writes:
> > Somewhere in the $(shlib) rule would seem most appropriate. But I don't
> > understand the rest: What ifeq, and why .DELETE_ON_ERROR?
>
> The variant of this I'd been thinking of was
>
> $(shlib): $(OBJS) | $(SHLIB_PREREQS)
> $(LINK.shared) -o $@ $(OBJS) $(LDFLAGS) $(LDFLAGS_SL) $(SHLIB_LINK)
> +ifneq (,$(SHLIB_EXTRA_ACTION))
> + $(SHLIB_EXTRA_ACTION)
> +endif
>
> (and similarly in several other places); then libpq's Makefile
> could set SHLIB_EXTRA_ACTION to the desired thing.
>
> The problem then is, what happens when the extra action fails?
> Without .DELETE_ON_ERROR, the shlib is still there and the next
> make run will think everything's good.
Yep, that was pretty much what was in my head. ifeq (or ifneq in your
example) to gate the extra nm check, and .DELETE_ON_ERROR to make the
failure stick for future make invocations.
--Jacob