Bug #326561 - Implement FEATURES=unknown-features-filter. This is not

enabled by default now, but it may be in the future, depending on feedback
from unknown-features-warn.

3 files changed, 65 insertions, 15 deletions

diff --git a/pym/portage/const.py b/pym/portage/const.py
index 7edb1f19f..cf24fcc31 100644
--- a/pym/portage/const.py
+++ b/pym/portage/const.py
@@ -97,7 +97,7 @@ SUPPORTED_FEATURES       = frozenset([
                            "selinux", "sesandbox", "severe", "sfperms",
                            "sign", "skiprocheck", "split-elog", "split-log", "splitdebug",
                            "strict", "stricter", "suidctl", "test", "test-fail-continue",
-                           "unknown-features-warn",
+                           "unknown-features-filter", "unknown-features-warn",
                            "unmerge-logs", "unmerge-orphans", "userfetch", "userpriv",
                            "usersandbox", "usersync", "webrsync-gpg"])
 
diff --git a/pym/portage/package/ebuild/_config/features_set.py b/pym/portage/package/ebuild/_config/features_set.py
index 7ab148fc8..a39fb89dc 100644
--- a/pym/portage/package/ebuild/_config/features_set.py
+++ b/pym/portage/package/ebuild/_config/features_set.py
@@ -5,6 +5,13 @@ __all__ = (
 	'features_set',
 )
 
+import logging
+
+from portage.const import SUPPORTED_FEATURES
+from portage.localization import _
+from portage.output import colorize
+from portage.util import writemsg_level
+
 class features_set(object):
 	"""
 	Provides relevant set operations needed for access and modification of
@@ -51,6 +58,15 @@ class features_set(object):
 		if need_sync:
 			self._sync_env_var()
 
+	def difference_update(self, values):
+		self._settings.modifying()
+		values = list(values)
+		self._settings._features_overrides.extend('-' + k for k in values)
+		remove_us = self._features.intersection(values)
+		if remove_us:
+			self._features.difference_update(values)
+			self._sync_env_var()
+
 	def remove(self, k):
 		"""
 		This never raises KeyError, since it records a permanent override
@@ -65,3 +81,49 @@ class features_set(object):
 		if k in self._features:
 			self._features.remove(k)
 			self._sync_env_var()
+
+	def _validate(self):
+		"""
+		Implements unknown-features-warn and unknown-features-filter.
+		"""
+		if 'unknown-features-warn' in self._features:
+			unknown_features = \
+				self._features.difference(SUPPORTED_FEATURES)
+			if unknown_features:
+				unknown_features = unknown_features.difference(
+					self._settings._unknown_features)
+				if unknown_features:
+					self._settings._unknown_features.update(unknown_features)
+					writemsg_level(colorize("BAD",
+						_("FEATURES variable contains unknown value(s): %s") % \
+						", ".join(sorted(unknown_features))) \
+						+ "\n", level=logging.WARNING, noiselevel=-1)
+
+		if 'unknown-features-filter' in self._features:
+			unknown_features = \
+				self._features.difference(SUPPORTED_FEATURES)
+			if unknown_features:
+				self.difference_update(unknown_features)
+				self._prune_overrides()
+
+	def _prune_overrides(self):
+		"""
+		If there are lots of invalid package.env FEATURES settings
+		then unknown-features-filter can make _features_overrides
+		grow larger and larger, so prune it. This performs incremental
+		stacking with preservation of negative values since they need
+		to persist for future config.regenerate() calls.
+		"""
+		overrides_set = set(self._settings._features_overrides)
+		if len(overrides_set) < len(self._settings._features_overrides):
+			positive = set()
+			negative = set()
+			for x in self._settings._features_overrides:
+				if x[:1] == '-':
+					positive.discard(x[:1])
+					negative.add(x[:1])
+				else:
+					positive.add(x)
+					negative.discard(x)
+			self._settings._features_overrides[:] = \
+				list(positive) + list(negative)
diff --git a/pym/portage/package/ebuild/config.py b/pym/portage/package/ebuild/config.py
index ab042a235..847ac1ccb 100644
--- a/pym/portage/package/ebuild/config.py
+++ b/pym/portage/package/ebuild/config.py
@@ -27,7 +27,7 @@ from portage import bsd_chflags, \
 from portage.const import CACHE_PATH, \
 	DEPCACHE_PATH, INCREMENTALS, MAKE_CONF_FILE, \
 	MODULES_FILE_PATH, PORTAGE_BIN_PATH, PORTAGE_PYM_PATH, \
-	PRIVATE_PATH, PROFILE_PATH, SUPPORTED_FEATURES, USER_CONFIG_PATH, \
+	PRIVATE_PATH, PROFILE_PATH, USER_CONFIG_PATH, \
 	USER_VIRTUALS_FILE
 from portage.dbapi import dbapi
 from portage.dbapi.porttree import portdbapi
@@ -1911,19 +1911,7 @@ class config(object):
 			self.features = features_set(self)
 		self.features._features.update(self.get('FEATURES', '').split())
 		self.features._sync_env_var()
-
-		if 'unknown-features-warn' in self.features:
-			unknown_features = \
-				self.features._features.difference(SUPPORTED_FEATURES)
-			if unknown_features:
-				unknown_features = \
-					unknown_features.difference(self._unknown_features)
-				if unknown_features:
-					self._unknown_features.update(unknown_features)
-					writemsg_level(colorize("BAD",
-						_("FEATURES variable contains unknown value(s): %s") % \
-						", ".join(sorted(unknown_features))) \
-						+ "\n", noiselevel=-1)
+		self.features._validate()
 
 		myflags.update(self.useforce)
 		arch = self.configdict["defaults"].get("ARCH")