blob: 34758ed1fe9d5038ec0d4a342a1a684b937836dd [file] [log] [blame]
#!/usr/bin/env python
# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Prints paths between gyp targets.
"""
import json
import os
import sys
import time
from collections import deque
def usage():
print """\
Usage:
tools/gyp-explain.py chrome_dll gtest#
"""
def GetPath(graph, fro, to):
"""Given a graph in (node -> list of successor nodes) dictionary format,
yields all paths from |fro| to |to|, starting with the shortest."""
# Storing full paths in the queue is a bit wasteful, but good enough for this.
q = deque([(fro, [])])
while q:
t, path = q.popleft()
if t == to:
yield path + [t]
for d in graph[t]:
q.append((d, path + [t]))
def MatchNode(graph, substring):
"""Given a dictionary, returns the key that matches |substring| best. Exits
if there's not one single best match."""
candidates = []
for target in graph:
if substring in target:
candidates.append(target)
if not candidates:
print 'No targets match "%s"' % substring
sys.exit(1)
if len(candidates) > 1:
print 'More than one target matches "%s": %s' % (
substring, ' '.join(candidates))
sys.exit(1)
return candidates[0]
def Main(argv):
if sys.platform in ['win32', 'cygwin']:
print 'The dump_dependency_json gyp generator required for gyp-explain.py'
print 'does not support Windows.'
sys.exit(1)
# Check that dump.json exists and that it's not too old.
dump_json_dirty = False
try:
st = os.stat('dump.json')
file_age_s = time.time() - st.st_mtime
if file_age_s > 2 * 60 * 60:
print 'dump.json is more than 2 hours old.'
dump_json_dirty = True
except OSError:
print 'dump.json not found.'
dump_json_dirty = True
if dump_json_dirty:
print 'Run'
print ' GYP_GENERATORS=dump_dependency_json build/gyp_chromium'
print 'first, then try again.'
sys.exit(1)
g = json.load(open('dump.json'))
if len(argv) != 3:
usage()
sys.exit(1)
fro = MatchNode(g, argv[1])
to = MatchNode(g, argv[2])
paths = list(GetPath(g, fro, to))
if len(paths) > 0:
print 'These paths lead from %s to %s:' % (fro, to)
for path in paths:
print ' -> '.join(path)
else:
print 'No paths found from %s to %s.' % (fro, to)
if __name__ == '__main__':
Main(sys.argv)