[Openembedded-architecture] Syntax for multiple overrides?

[Richard Purdie]

I'm not 100% sure whether I like this idea or not but wanted to share
it and see what others think.

We're looking at a recipe which would do:

BBCLASSEXTEND = "devupstream:target"
LIC_FILES_CHKSUM_class-devupstream = "file://LICENSE;md5=3f882d431dc0f32f1f44c0707aa41128"
DEFAULT_PREFERENCE_class-devupstream = "-1"
SRC_URI_class-devupstream = "git://git.lttng.org/lttng-modules;branch=master \
           file://Makefile-Do-not-fail-if-CONFIG_TRACEPOINTS-is-not-en.patch \
           file://BUILD_RUNTIME_BUG_ON-vs-gcc7.patch \
           "
SRCREV_class-devupstream = "${AUTOREV}"
PV_class-devupstream = "2.11.0-rc+git${SRCPV}"
S_class-devupstream = "${WORKDIR}/git"

which is a bit ugly. I wondered whether we'd want to support some kind
of collective override syntax, e.g.:

BBCLASSEXTEND = "devupstream:target"
override class-devupstream {
LIC_FILES_CHKSUM = "file://LICENSE;md5=3f882d431dc0f32f1f44c0707aa41128"
DEFAULT_PREFERENCE = "-1"
SRC_URI = "git://git.lttng.org/lttng-modules;branch=master \
           file://Makefile-Do-not-fail-if-CONFIG_TRACEPOINTS-is-not-en.patch \
           file://BUILD_RUNTIME_BUG_ON-vs-gcc7.patch \
           "
SRCREV = "${AUTOREV}"
PV = "2.11.0-rc+git${SRCPV}"
S = "${WORKDIR}/git"
}

It would be a pain to implement in bitbake but should be possible, it
would literally just append _<OVERRIDE> to the variable names when
storing them.

I've been toying with ideas around making a syntax around conditional
blocks, the trouble is such things would imply immediate expansion
which wouldn't work in many cases.

Just thinking out loud really...

Cheers,

Richard