On Sun, Feb 03, 2019 at 10:31:26AM -0500, Tom Lane wrote: > Noah Misch <n...@leadboat.com> writes: > > The -Wno-declaration-after-statement approach takes eight lines of code, and > > the filter-out approach takes one. On the other hand, using $(filter-out) > > changes any runs of whitespace to single spaces ("$(filter-out foo,a b > > c)" > > yields "a b c"). We do risk that with CPPFLAGS and LDFLAGS in a few places. > > I don't want to proliferate that practice, because it changes semantics of > > CFLAGS containing -DFOO="arbitrary text". > > I don't particularly buy that argument, because CPPFLAGS is where any -D > switches ought to be put. So we've already exposed ourselves to this > risk, in the unlikely scenario where it's not hypothetical.
The $(filter-out) corruption is unlikely to matter, indeed. The question is whether to use eight lines of code to inject -Wno-declaration-after-statement or one line to remove -Wdeclaration-after-statement using $(filter-out). I see negligible drawbacks on either side; both approaches are tolerable. The above-described hypothetical problem tips the scale in favor of -Wno-declaration-after-statement.