On Mon, Feb 19, 2018 at 10:01:49AM -0800, Linus Torvalds wrote: > On Mon, Feb 19, 2018 at 9:44 AM, Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > I do like your "success"/"stdout" more than "shell"/"shell-stdout", > > because with that naming I don't get the feeling that one should > > subsume the other. > > Hmm. Thinking about it some more, I really would prefer just "$(shell > ...)" everywhere. > > But it would be nice if perhaps the error handling would match the > context somehow. > > I'm wondering if this might tie into the whole quoting discussion in > the other thread. > > Because the rule could be: > > (a) unquoted $(shell ) is a bool, and failing is ok (and turns into > y/n depending on whether successful or failing) > > So > > config CC_IS_GCC > bool > default $(shell $CC --version | grep -q gcc) > > works automatically. > > (b) but with quoting, $(shell ) is a string, and failing is an error > > So > > config GCC_VERSION > int > default "$(shell-stdout $srctree/scripts/gcc-version.sh $CC > | sed 's/^0*//')" if CC_IS_GCC > default 0 > > would need those quotes, and if the shell-script returns a failure, > we'd _abort_. > > Which is actually what we want there. > > Hmm? Is that too nasty? > > Linus One minor drawback would be slight kludginess if you want "n"/"y" put into a string depending on the success of a command: default "foo-$(shell cmd && echo y || echo n)" As opposed to: default "foo-$(success cmd)" I don't know if that's significant enough to matter in practice. Keeping it objective, I can't see any major downsides, though I'd really prefer to just have $() do string interpolation within "". That keeps the implementation trivial and makes the behavior and limitations obvious once you know that n/m/y is just shorthand for "n"/"m"/"y". Cheers, Ulf -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
