[oe] is it "PROVIDES =" or "PROVIDES +=" for setting an alternate name?

[Christopher Larson]

On Sat, Jul 12, 2014 at 4:28 AM, Robert P. J. Day <rpjday at crashcourse.ca>
wrote:

>   i notice that the OE-core codebase likes to mix these two forms of
> using PROVIDES. for instance, for a number of libraries to provide
> their basename, i see stuff like:
>
> recipes-graphics/xorg-lib/libxmu_1.1.2.bb:PROVIDES = "xmu"
> recipes-graphics/xorg-lib/libice_1.0.8.bb:PROVIDES = "ice"
> recipes-graphics/xorg-lib/libxdamage_1.1.4.bb:PROVIDES = "xdamage"
> recipes-graphics/xorg-lib/libxfont_1.4.7.bb:PROVIDES = "xfont"
> recipes-graphics/xorg-lib/libxdmcp_1.1.1.bb:PROVIDES = "xdmcp"
>
>   on the other hand, there is the occasional example of the same thing
> that uses "PROVIDES +=" instead:
>
> recipes-support/libpcre/libpcre_8.35.bb:PROVIDES += "pcre"
>
> is there a deliberate distinction made in the recipes between these
> two forms?
>

I don't think there's ever a valid reason to not use +=, unless it
explicitly wants to remove something. That said, bitbake hardcodes addition
of ${PN} to the PROVIDES list regardless of what the recipe says, so I
expect from a practical perspective there isn't a difference. That said, I
do think they should be switched to += to more accurately reflect the
intent, and to improve future compatibility (e.g. if the default PROVIDES
in bitbake.conf were to change).
-- 
Christopher Larson
clarson at kergoth dot com
Founder - BitBake, OpenEmbedded, OpenZaurus
Maintainer - Tslib
Senior Software Engineer, Mentor Graphics