On Tue, 16 Jul 2013 10:08:07 +0200 "Yann E. MORIN" <yann.morin.1998@xxxxxxx> wrote: > > Or, easier and faster, run some front-end script which generates > > once-off Kconfig symbols. > > > > if [ -x /bin/lz4c ] > > then > > echo CONFIG_HAVE_LZ4C > > fi > > > > then munge the output of that script into the Kconfig run and do > > > > depends on HAVE_LZ4C > > Yes, this is a better solution. > > For what it's worth, this is what I'm doing in crosstool-NG: a script > checks for optional pre-requisites, spits out a Kconfig blob which is > included by the top-level Kconfig file. > > Here is a snippet of generated Kconfig blob: > config HAVE_XZ > def_bool y > config HAVE_LZMA > bool > > Which means we do have 'xz', but not 'lzma'. This is relatively trivial > to do, so I'll tackle this this evening when I'm back home (unless > someone beats me to it). Cool, thanks. It seems a bit inefficient to be evaluating commands in a Kconfig setting where doesn't need that done. For example, if someone has selected LZO compression then they don't need to probe for lz4c. That example sounds hard to solve in a simple fashion, but what about the case where the config system is not going to look at an entire subsystem? Suppose for example, drivers/media/firewire wants to probe for some executable, but the user hasn't selected firewire at all. What I'm angling at is, rather than a single global front-end script, can we embed the scripts in some fashion within the various Kconfig files? Say, script ./some-script.sh and the config system will only evaluate that command if it is working on that Kconfig file. Obviously that requires a multiple-pass thing. It's late, but you see what I mean ;) -- 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
