[gentoo-portage-dev] [PATCH] Support USE_EXPAND prefixes in package.use and relevant files

["Michał Górny" <mgorny@gentoo.org>]

Support prefixing groups of USE_EXPAND flags with 'USE_EXPAND:' in user
configuration package.use and similar files. This provides a convenient
way of declaring specifying multiple USE_EXPAND flags and matches the
syntax supported by Paludis. Example:

  dev-util/netbeans NETBEANS_MODULES: php webcommon extide
  media-libs/mesa osmesa VIDEO_CARDS: intel nouveau
---
 pym/portage/package/ebuild/_config/UseManager.py | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/pym/portage/package/ebuild/_config/UseManager.py b/pym/portage/package/ebuild/_config/UseManager.py
index 3a4ec22..59f474e 100644
--- a/pym/portage/package/ebuild/_config/UseManager.py
+++ b/pym/portage/package/ebuild/_config/UseManager.py
@@ -202,10 +202,17 @@ class UseManager(object):
 		useflag_re = _get_useflag_re(eapi)
 		for k, v in file_dict.items():
 			useflags = []
+			use_expand_prefix = ''
 			for prefixed_useflag in v:
+				if extended_syntax and prefixed_useflag[-1] == ":":
+					use_expand_prefix = prefixed_useflag[:-1].lower() + "_"
+					continue
+
 				if prefixed_useflag[:1] == "-":
 					useflag = prefixed_useflag[1:]
+					prefixed_useflag = "-" + use_expand_prefix + useflag
 				else:
+					prefixed_useflag = use_expand_prefix + prefixed_useflag
 					useflag = prefixed_useflag
 				if useflag_re.match(useflag) is None:
 					writemsg(_("--- Invalid USE flag for '%s' in '%s': '%s'\n") %
@@ -227,7 +234,18 @@ class UseManager(object):
 			pusedict = grabdict_package(
 				os.path.join(location, file_name), recursive=1, allow_wildcard=True, allow_repo=True, verify_eapi=False)
 			for k, v in pusedict.items():
-				ret.setdefault(k.cp, {})[k] = tuple(v)
+				l = []
+				use_expand_prefix = ''
+				for flag in v:
+					if flag[-1] == ":":
+						use_expand_prefix = flag[:-1].lower() + "_"
+						continue
+					if flag[0] == "-":
+						nv = "-" + use_expand_prefix + flag[1:]
+					else:
+						nv = use_expand_prefix + flag
+					l.append(nv)
+				ret.setdefault(k.cp, {})[k] = tuple(l)
 
 		return ret
 
-- 
2.2.1