On Mon, Feb 06, 2017 at 01:22:08PM +0100, Paolo Bonzini wrote: > > > On 06/02/2017 13:05, Daniel P. Berrange wrote: > >>> $(shell mkdir -p ./ $(sort $(dir $($v)))) > >>> - $(shell cd $(BUILD_DIR) && mkdir -p ./ $(sort $(dir $($v)))) > >> I know this is the same syntax as the existing line above > >> and we're deleting it anyway, but what does it actually do? > >> When does telling mkdir to create "./" make sense? > > No idea why the ./ was there originally - it appears to serve no > > purpose. The useful bit is the stuff afterwards - the $($v) bit. > > It gets populated based on the variable being unnested. For example > > > > block-obj-y = block.o blockjob.o block/ nbd/ > > > > will make $v contain "block nbd", hence cause creation of those > > dirs in the the build dir. > > "mkdir -p" with no arguments gives an error, the "./" shuts it up.
Ah yes, clever. So that deals with case of unnesting a variable which does not contain any nested dirs. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|
