On Tue, Aug 16, 2016 at 4:02 PM, Robert P. J. Day <rpj...@crashcourse.ca> wrote: > > was about to submit a small number of patches to clean up redundancy > when people combine "_append" with "+=" (because it offends my > delicate sensibilities), and ran across this in oe-core, > unfs3_0.9.22.r497.bb: > > DEPENDS_append_class-nativesdk += "flex-nativesdk" > > uh, what? > > most of the time, i assume the above doesn't hurt, it's just ... > silly. but normally, with "_append", you *need* to add the leading > space explicitly, and that's not being done above. so does that mean > that combining "_append" with "+=" *does* generate a leading space? > that just makes my head hurt -- the possibility that "_append" is > being used in a way that normally makes it fail, only to have "+=" > step in and save the day. at which point "_append" saves processing > that until the end of parsing? yeesh. > > thoughts?
By the point the += is handled, the override won't have been interpreted yet. My guess is that += fetches the value of the variable "DEPENDS_append_class-nativesdk", gets back the empty string, and adds a space followed by "flex-nativesdk" to that. The resulting " flex-nativesdk" is then interpreted as usual when the overrides are handled. You might like the note I added to https://www.yoctoproject.org/docs/2.2/bitbake-user-manual/bitbake-user-manual.html#override-style-operation-advantages by the way. :) Cheers, Ulf -- _______________________________________________ Openembedded-core mailing list Openembedded-core@lists.openembedded.org http://lists.openembedded.org/mailman/listinfo/openembedded-core
