Add build target for nacl_io from the NaCl SDK.

native_client_sdk/src/build_tools/dsc_info.py

Index: native_client_sdk/src/build_tools/dsc_info.py
diff --git a/native_client_sdk/src/build_tools/dsc_info.py b/native_client_sdk/src/build_tools/dsc_info.py
new file mode 100755
index 0000000000000000000000000000000000000000..e5bb048747f5909b70ec3cb10649529f7f4f0fbb
--- /dev/null
+++ b/native_client_sdk/src/build_tools/dsc_info.py
@@ -0,0 +1,65 @@
+#!/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: %s' % msg
+  sys.exit(1)
+
+
+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):
+  "Entry point for gyp's pymod_do_main command."
+  parser = optparse.OptionParser(usage='%prog: [OPTIONS] TARGET')
+  # Give a clearer error message when this is used as a module.
+  parser.prog = 'dsc_info'
+  parser.add_option('-s', '--sources',
+                    help='Print a list of source files for the target',
+                    action='store_true', default=False)
+  parser.add_option('-l', '--libdir',
+                    help='Directory where the library.dsc file is located',
+                    metavar='DIR')
+  options, args = parser.parse_args(argv)
+  if len(args) != 1:
+    parser.error('Expecting exactly one argument.')
+  target = args[0]
+  libdir = options.libdir or ''
+  tree = parse_dsc.LoadProject(os.path.join(libdir, 'library.dsc'))
+  if options.sources:
+    return '\n'.join(GetSources(libdir, tree, target))
+  parser.error('No action specified')
+
+
+def main(argv):
+  print DoMain(argv[1:])
+
+
+if __name__ == '__main__':
+  try:
+    sys.exit(main(sys.argv))
+  except KeyboardInterrupt:
+    Error('interrupted')