Add build target for nacl_io from the NaCl SDK.

native_client_sdk/src/build_tools/dsc_info.py

+#!/usr/bin/env python
+# Copyright (c) 2013 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.
+
+"""Extracts information from a library.dsc file."""
+
+import optparse
+import os
+import sys
+
+import parse_dsc
+
+def Error(msg):
+  print >> sys.stderr, 'dsc_info: msg'

[binji, 2013/11/12 19:41:42]

'dsc_info: %s' % msg

+  sys.exit(1)
+

[binji, 2013/11/12 19:41:42]

nit: two lines between top-level functions

+def FindTarget(tree, target_name):
+  targets = tree['TARGETS']
+  for target in targets:
+    if target['NAME'] == target_name:
+      return target
+  Error('Target %s not found' % target_name)
+
+def GetSources(lib_dir, tree, target_name):
+  result = []
+  target = FindTarget(tree, target_name)
+  for filename in target['SOURCES']:
+    result.append('/'.join([lib_dir, filename]))
+  return result
+
+def DoMain(argv):

[binji, 2013/11/12 19:41:42]

we usually just have:

def main(args):

and pass args[1:] to parse_args

+  "Entry point for gyp's pymod_do_main command."
+  parser = optparse.OptionParser(usage='%prog [OPTIONS] LIB_DIR')
+  parser.add_option('-s', '--sources',
+                    help='Print a list of source for the target',
+                    action='store_true', default=False)
+  parser.add_option('-t', '--target',

[binji, 2013/11/12 19:41:42]

use positional args for this instead, and have a optional arg for the lib_dir.

+                    help='Target to display information for')
+  options, args = parser.parse_args(argv)
+  if len(args) != 1:
+    parser.error('Wrong numer of arguments')

[binji, 2013/11/12 19:41:42]

sp: number

+  lib_dir = args[0]
+  tree = parse_dsc.LoadProject(os.path.join(lib_dir, 'library.dsc'))
+  if options.sources:
+    if not options.target:
+      parser.error('Missing --target')
+    return '\n'.join(GetSources(lib_dir, tree, options.target))
+  parser.error('No action specified')
+
+def main(argv):
+  print DoMain(argv[1:])
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))

[binji, 2013/11/12 19:41:42]

for consistency, please add KeyboardInterrupt exception check (like build_sdk,
test_sdk, etc)