| #!/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 [--dot] 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 EscapeForDot(string): |
| suffix = '#target' |
| if string.endswith(suffix): |
| string = string[:-len(suffix)] |
| string = string.replace('\\', '\\\\') |
| return '"' + string + '"' |
| |
| |
| def GenerateDot(fro, to, paths): |
| """Generates an input file for graphviz's dot program.""" |
| prefixes = [os.path.commonprefix(path) for path in paths] |
| prefix = os.path.commonprefix(prefixes) |
| print '// Build with "dot -Tpng -ooutput.png this_file.dot"' |
| # "strict" collapses common paths. |
| print 'strict digraph {' |
| for path in paths: |
| print (' -> '.join(EscapeForDot(item[len(prefix):]) for item in path)), ';' |
| print '}' |
| |
| |
| def Main(argv): |
| # 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) not in (3, 4): |
| usage() |
| sys.exit(1) |
| |
| generate_dot = argv[1] == '--dot' |
| if generate_dot: |
| argv.pop(1) |
| |
| fro = MatchNode(g, argv[1]) |
| to = MatchNode(g, argv[2]) |
| |
| paths = list(GetPath(g, fro, to)) |
| if len(paths) > 0: |
| if generate_dot: |
| GenerateDot(fro, to, paths) |
| else: |
| 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) |