[OE-core] [PATCH 1/1] conf/bitbake.conf: add DISTRO_FEATURES_BACKFILL
Paul Eggleton
paul.eggleton at linux.intel.com
Thu Feb 23 19:26:09 UTC 2012
When introducing new items to DISTRO_FEATURES that control functionality
that is already enabled, in order to leave existing distro configuration
unchanged we need a way to "backfill" these new feature items onto the
existing DISTRO_FEATURES value.
This introduces a DISTRO_FEATURES_BACKFILL variable whose items will be
added to the end of DISTRO_FEATURES, unless they also appear in
DISTRO_FEATURES_BACKFILL_CONSIDERED which distros can use in their
configuration to prevent specific items from being added.
Fixes [YOCTO #1946].
Signed-off-by: Paul Eggleton <paul.eggleton at linux.intel.com>
---
meta/conf/bitbake.conf | 3 +++
meta/lib/oe/utils.py | 20 ++++++++++++++++++++
2 files changed, 23 insertions(+), 0 deletions(-)
diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 90e5f7a..2539ae0 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -694,6 +694,9 @@ MACHINE_ESSENTIAL_EXTRA_RDEPENDS ?= ""
MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS ?= ""
IMAGE_FEATURES += "${EXTRA_IMAGE_FEATURES}"
+DISTRO_FEATURES_BACKFILL = ""
+DISTRO_FEATURES_append = "${@oe.utils.distro_features_backfill(d)}"
+
COMBINED_FEATURES = "\
${@base_both_contain("DISTRO_FEATURES", "MACHINE_FEATURES", "alsa", d)} \
${@base_both_contain("DISTRO_FEATURES", "MACHINE_FEATURES", "bluetooth", d)} \
diff --git a/meta/lib/oe/utils.py b/meta/lib/oe/utils.py
index 95daace..2aaed3a 100644
--- a/meta/lib/oe/utils.py
+++ b/meta/lib/oe/utils.py
@@ -88,3 +88,23 @@ def param_bool(cfg, field, dflt = None):
def inherits(d, *classes):
"""Return True if the metadata inherits any of the specified classes"""
return any(bb.data.inherits_class(cls, d) for cls in classes)
+
+def distro_features_backfill(d):
+ # This construct allows the addition of new features to DISTRO_FEATURES
+ # that if not present would disable existing functionality, without
+ # disturbing distributions that have already set DISTRO_FEATURES.
+ # Distributions wanting to elide a value in DISTRO_FEATURES_BACKFILL should
+ # add the feature to DISTRO_FEATURES_BACKFILL_CONSIDERED
+
+ backfill = (d.getVar("DISTRO_FEATURES_BACKFILL", True) or "").split()
+ considered = (d.getVar("DISTRO_FEATURES_BACKFILL_CONSIDERED", True) or "").split()
+
+ addfeatures = []
+ for feature in backfill:
+ if feature not in considered:
+ addfeatures.append(feature)
+
+ if addfeatures:
+ return " %s" % (" ".join(addfeatures))
+ else:
+ return ""
--
1.7.5.4
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