1#!/usr/bin/env python
2
3# Copyright (c) 2011 Google Inc. All rights reserved.
4# Use of this source code is governed by a BSD-style license that can be
5# found in the LICENSE file.
6
7"""Using the JSON dumped by the dump-dependency-json generator,
8generate input suitable for graphviz to render a dependency graph of
9targets."""
10
11import collections
12import json
13import sys
14
15
16def ParseTarget(target):
17  target, _, suffix = target.partition('#')
18  filename, _, target = target.partition(':')
19  return filename, target, suffix
20
21
22def LoadEdges(filename, targets):
23  """Load the edges map from the dump file, and filter it to only
24  show targets in |targets| and their depedendents."""
25
26  file = open('dump.json')
27  edges = json.load(file)
28  file.close()
29
30  # Copy out only the edges we're interested in from the full edge list.
31  target_edges = {}
32  to_visit = targets[:]
33  while to_visit:
34    src = to_visit.pop()
35    if src in target_edges:
36      continue
37    target_edges[src] = edges[src]
38    to_visit.extend(edges[src])
39
40  return target_edges
41
42
43def WriteGraph(edges):
44  """Print a graphviz graph to stdout.
45  |edges| is a map of target to a list of other targets it depends on."""
46
47  # Bucket targets by file.
48  files = collections.defaultdict(list)
49  for src, dst in edges.items():
50    build_file, target_name, toolset = ParseTarget(src)
51    files[build_file].append(src)
52
53  print 'digraph D {'
54  print '  fontsize=8'  # Used by subgraphs.
55  print '  node [fontsize=8]'
56
57  # Output nodes by file.  We must first write out each node within
58  # its file grouping before writing out any edges that may refer
59  # to those nodes.
60  for filename, targets in files.items():
61    if len(targets) == 1:
62      # If there's only one node for this file, simplify
63      # the display by making it a box without an internal node.
64      target = targets[0]
65      build_file, target_name, toolset = ParseTarget(target)
66      print '  "%s" [shape=box, label="%s\\n%s"]' % (target, filename,
67                                                     target_name)
68    else:
69      # Group multiple nodes together in a subgraph.
70      print '  subgraph "cluster_%s" {' % filename
71      print '    label = "%s"' % filename
72      for target in targets:
73        build_file, target_name, toolset = ParseTarget(target)
74        print '    "%s" [label="%s"]' % (target, target_name)
75      print '  }'
76
77  # Now that we've placed all the nodes within subgraphs, output all
78  # the edges between nodes.
79  for src, dsts in edges.items():
80    for dst in dsts:
81      print '  "%s" -> "%s"' % (src, dst)
82
83  print '}'
84
85
86def main():
87  if len(sys.argv) < 2:
88    print >>sys.stderr, __doc__
89    print >>sys.stderr
90    print >>sys.stderr, 'usage: %s target1 target2...' % (sys.argv[0])
91    return 1
92
93  edges = LoadEdges('dump.json', sys.argv[1:])
94
95  WriteGraph(edges)
96  return 0
97
98
99if __name__ == '__main__':
100  sys.exit(main())
101