[OE-core] value of "PACKAGE_BEFORE_PN" versus "PACKAGES =+"?

[Saul Wold]

On 01/02/2013 09:04 AM, Robert P. J. Day wrote:
>
>    just now noticed the variable PACKAGE_BEFORE_PN, whose entire
> usage in poky (other than documentation) is:
>
> meta/conf/bitbake.conf:PACKAGE_BEFORE_PN ?= ""
> meta/conf/bitbake.conf:PACKAGES = "${PN}-dbg ${PN}-staticdev ${PN}-dev ${PN}-doc ${PN}-locale ${PACKAGE_BEFORE_PN} ${PN}"
> meta/classes/lib_package.bbclass:PACKAGE_BEFORE_PN = "${PN}-bin"
>
>    is there an actual need for that variable that places the new
> package names *precisely* in that location in the PACKAGES list?  and
> given the specificity of the initial PN-related packages:
>
Yes, the need in the case of lib_package it to ensure that the ${PN}-bin 
(bindir and sbindir) files get packages separately from the ${PN} files, 
which are typically the libraries in the case of recipes that deliver 
libraries and binaries.

>    "${PN}-dbg ${PN}-staticdev ${PN}-dev ${PN}-doc ${PN}-locale"
>
> is there any reason more recipes couldn't use PACKAGE_BEFORE_PN
> instead of "PACKAGES =+" when defining new packages?  i *realize*
> those two things don't represent the same thing but, in many cases,
> would the end result be the same?
>
>    is there any reason more code doesn't use "PACKAGE_BEFORE_PN"?
>
The =+ prepends it to the list and therefore is correctly greedy for the 
items they are trying to package. Since the PACKAGE_BEFORE_PN 
specifically inserts it, so for the most part there is no real need to 
use the P_B_P variable, and =+ is more consistent.

Sau!


> rday