[gentoo-portage-dev] [PATCH 2/3] sets: Introduce @changed-deps to update packages which need dep changes

[Michał Górny]

The @changed-deps set tries to compare RDEPEND and PDEPEND entries of
installed packages with ebuild counterparts, and pulls the ebuild
whenever the two are not in sync. This could be used, for example, to
clean up the system after disabling --dynamic-deps.
---
 cnf/sets/portage.conf      |  5 +++
 pym/portage/_sets/dbapi.py | 81 ++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/cnf/sets/portage.conf b/cnf/sets/portage.conf
index b73afb1..fd2c387 100644
--- a/cnf/sets/portage.conf
+++ b/cnf/sets/portage.conf
@@ -84,3 +84,8 @@ class = portage.sets.dbapi.UnavailableSet
 # are not available.
 [unavailable-binaries]
 class = portage.sets.dbapi.UnavailableBinaries
+
+# Installed packages for which vdb *DEPEND entries are outdated compared
+# to the matching portdb entry.
+[changed-deps]
+class = portage.sets.dbapi.ChangedDepsSet
diff --git a/pym/portage/_sets/dbapi.py b/pym/portage/_sets/dbapi.py
index 817bcd7..299cb81 100644
--- a/pym/portage/_sets/dbapi.py
+++ b/pym/portage/_sets/dbapi.py
@@ -3,17 +3,19 @@
 
 from __future__ import division
 
+import re
 import time
 
 from portage import os
 from portage.versions import best, catsplit, vercmp
-from portage.dep import Atom
+from portage.dep import Atom, use_reduce
+from portage.exception import InvalidAtom
 from portage.localization import _
 from portage._sets.base import PackageSet
 from portage._sets import SetConfigError, get_boolean
 import portage
 
-__all__ = ["CategorySet", "DowngradeSet",
+__all__ = ["CategorySet", "ChangedDepsSet", "DowngradeSet",
 	"EverythingSet", "OwnerSet", "VariableSet"]
 
 class EverythingSet(PackageSet):
@@ -458,3 +460,78 @@ class RebuiltBinaries(EverythingSet):
 			bindb=trees["bintree"].dbapi)
 
 	singleBuilder = classmethod(singleBuilder)
+
+class ChangedDepsSet(PackageSet):
+
+	_operations = ["merge", "unmerge"]
+
+	description = "Package set which contains all installed " + \
+		"packages for which the vdb *DEPEND entries are outdated " + \
+		"compared to corresponding portdb entries."
+
+	def __init__(self, portdb=None, vardb=None):
+		super(ChangedDepsSet, self).__init__()
+		self._portdb = portdb
+		self._vardb = vardb
+
+	def load(self):
+		depvars = ('RDEPEND', 'PDEPEND')
+
+		# regexp used to match atoms using subslot operator :=
+		subslot_repl_re = re.compile(r':[^[]*=')
+
+		atoms = []
+		for cpv in self._vardb.cpv_all():
+			# no ebuild, no update :).
+			if not self._portdb.cpv_exists(cpv):
+				continue
+
+			# USE flags used to build the ebuild and EAPI
+			# (needed for Atom & use_reduce())
+			use, eapi = self._vardb.aux_get(cpv, ('USE', 'EAPI'))
+			usel = use.split()
+
+			# function used to recursively process atoms in nested lists.
+			def clean_subslots(depatom, usel=None):
+				if isinstance(depatom, list):
+					# process the nested list.
+					return [clean_subslots(x, usel) for x in depatom]
+				else:
+					try:
+						# this can be either an atom or some special operator.
+						# in the latter case, we get InvalidAtom and pass it as-is.
+						a = Atom(depatom)
+					except InvalidAtom:
+						return depatom
+					else:
+						# if we're processing portdb, we need to evaluate USE flag
+						# dependency conditionals to make them match vdb. this
+						# requires passing the list of USE flags, so we reuse it
+						# as conditional for the operation as well.
+						if usel is not None:
+							a = a.evaluate_conditionals(usel)
+
+						# replace slot operator := dependencies with plain :=
+						# since we can't properly compare expanded slots
+						# in vardb to abstract slots in portdb.
+						return subslot_repl_re.sub(':=', a)
+
+			# get all *DEPEND variables from vdb & portdb and compare them.
+			# we need to do some cleaning up & expansion to make matching
+			# meaningful since vdb dependencies are conditional-free.
+			vdbvars = [clean_subslots(use_reduce(x, uselist=usel, eapi=eapi))
+					for x in self._vardb.aux_get(cpv, depvars)]
+			pdbvars = [clean_subslots(use_reduce(x, uselist=usel, eapi=eapi), usel)
+					for x in self._portdb.aux_get(cpv, depvars)]
+
+			# if dependencies don't match, trigger the rebuild.
+			if vdbvars != pdbvars:
+				atoms.append('=%s' % cpv)
+
+		self._setAtoms(atoms)
+
+	def singleBuilder(cls, options, settings, trees):
+		return cls(portdb=trees["porttree"].dbapi,
+			vardb=trees["vartree"].dbapi)
+
+	singleBuilder = classmethod(singleBuilder)
-- 
2.0.4