Add a tool to find reverse dependencies.

1 files changed, 78 insertions, 0 deletions

diff --git a/reverse-dependencies.py b/reverse-dependencies.py
new file mode 100755
index 0000000..88d79aa
--- /dev/null
+++ b/reverse-dependencies.py
@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+# Copyright 2011 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+import optparse
+import os
+import types
+
+os.environ["PORTDIR_OVERLAY"] = ""
+
+import portage
+
+def process_deps(deps, use=None):
+	if not use:
+		use = []
+	result = []
+	for index, x in enumerate(deps):
+		if type(x) == types.ListType:
+			continue
+		elif x == "||":  # Any-of.
+			result.extend(process_deps(deps[index + 1], use))
+		elif x[-1] == "?":  # Use-conditional.
+			result.extend(process_deps(deps[index + 1], use + [x[:-1]]))
+		elif x[0] == "!":  # Blocker.
+			result.append((portage.dep_getkey(x), True, use))
+		else:
+			result.append((portage.dep_getkey(x), False, use))
+	return result
+
+if __name__ == "__main__":
+	parser = optparse.OptionParser()
+	parser.add_option("-i", "--input", dest="input_filename", default="package.keywords", help="Input filename for generated package.keywords file [default=%default]")
+	parser.add_option("-o", "--output", dest="output_filename", default="package.rdeps", help="Output filename for generated package.rdeps file [default=%default]")
+	parser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False)
+
+	(options, args) = parser.parse_args()
+	if not options.input_filename:
+		parser.error("--input option is required")
+	if not options.output_filename:
+		parser.error("--output option is required")
+	if args:
+		parser.error("unrecognized command-line args")
+
+	reverse_deps = {}
+	for pkg in portage.portdb.cp_all():
+		deps = []
+		for match in portage.portdb.match(pkg):
+			deps.extend(process_deps(portage.dep.paren_reduce(portage.portdb.aux_get(match, ['DEPEND', 'RDEPEND', 'PDEPEND'])[0])))
+		for cp, blocker, use in deps:
+			if blocker:
+				continue
+			if cp not in reverse_deps:
+				reverse_deps[cp] = {}
+			if pkg not in reverse_deps[cp]:
+				reverse_deps[cp][pkg] = []
+			if use not in reverse_deps[cp][pkg]:
+				reverse_deps[cp][pkg].append(use)
+
+	with open(options.input_filename, "r") as input_file:
+		with open(options.output_filename, "w") as output_file:
+			for line in input_file:
+				if line == "\n" or line.startswith("#"):
+					continue
+
+				if not line.endswith("\n"):
+					line += "\n"
+				cpv = line[1:-1]
+				pn = portage.versions.pkgsplit(cpv)[0]
+				if pn in reverse_deps:
+					output_file.write("# Reverse dependencies for %s\n" % pn)
+					for cp, use_combinations in reverse_deps[pn].items():
+						if use_combinations != [[]]:
+							output_file.write("# One of the following USE flag combinations is required:\n")
+							for use_combination in use_combinations:
+								output_file.write("#\t%s\n" % ",".join(use_combination))
+						output_file.write("%s\n" % cp)
+				elif options.verbose:
+					print 'No reverse dependencies for %s' % pn