Fuchsia: Adds a script to make a jiri manifest for third_party/pkg stuff

tools/create_pkg_manifest.py

Index: tools/create_pkg_manifest.py
diff --git a/tools/create_pkg_manifest.py b/tools/create_pkg_manifest.py
new file mode 100755
index 0000000000000000000000000000000000000000..5affb96034b66c22b809f21f2d70b7837d9a9be1
--- /dev/null
+++ b/tools/create_pkg_manifest.py
@@ -0,0 +1,108 @@
+#!/usr/bin/env python
+# Copyright 2016 The Dart project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Usage: create_pkg_manifest.py --deps <DEPS file> --output <jiri manifest>
+#
+# This script parses the DEPS file, extracts dependencies that live under
+# third_party/pkg, and writes them to a file suitable for consumption as a
+# jiri manifest for Fuchsia. It is assumed that the Dart tree is under
+# //dart in the Fuchsia world, and so the dependencies extracted by this script
+# will go under //dart/third_party/pkg.
+
+import argparse
+import os
+import sys
+import utils
+
+SCRIPT_DIR = os.path.dirname(sys.argv[0])
+DART_ROOT = os.path.realpath(os.path.join(SCRIPT_DIR, '..'))
+
+# Used in parsing the DEPS file.
+class VarImpl(object):
+  def __init__(self, local_scope):
+    self._local_scope = local_scope
+
+  def Lookup(self, var_name):
+    """Implements the Var syntax."""
+    if var_name in self._local_scope.get("vars", {}):
+      return self._local_scope["vars"][var_name]
+    raise Exception("Var is not defined: %s" % var_name)
+
+
+def ParseDepsFile(deps_file):
+  local_scope = {}
+  var = VarImpl(local_scope)
+  global_scope = {
+    'Var': var.Lookup,
+    'deps_os': {},
+  }
+  # Read the content.
+  with open(deps_file, 'r') as fp:
+    deps_content = fp.read()
+
+  # Eval the content.
+  exec(deps_content, global_scope, local_scope)
+
+  # Extract the deps and filter.
+  deps = local_scope.get('deps', {})
+  filtered_deps = {}
+  for k, v in deps.iteritems():
+    if 'sdk/third_party/pkg' in k:
+      new_key = k.replace('sdk', 'dart', 1)
+      filtered_deps[new_key] = v
+
+  return filtered_deps
+
+
+def WriteManifest(deps, manifest_file):
+  project_template = """
+    <project name="%s"
+             path="%s"
+             remote="%s"
+             revision="%s"/>
+  """
+  warning = ('<!-- This file is generated by '
+             '//dart/tools/create_pkg_manifest.py. DO NOT EDIT -->\n')
+  with open(manifest_file, 'w') as manifest:
+    manifest.write(warning)
+    manifest.write('<?xml version="1.0" encoding="UTF-8"?>\n')
+    manifest.write('<manifest>\n')
+    manifest.write('  <projects>\n')
+    for path, remote in deps.iteritems():
+      remote_components = remote.split('@')
+      remote_url = remote_components[0]
+      remote_version = remote_components[1]
+      manifest.write(
+          project_template % (path, path, remote_url, remote_version))
+    manifest.write('   </projects>\n')
+    manifest.write('</manifest>\n')
+
+
+def ParseArgs(args):
+  args = args[1:]
+  parser = argparse.ArgumentParser(
+      description='A script to generate a jiri manifest for third_party/pkg.')
+
+  parser.add_argument('--deps', '-d',
+      type=str,
+      help='Input DEPS file.',
+      default=os.path.join(DART_ROOT, 'DEPS'))
+  parser.add_argument('--output', '-o',
+      type=str,
+      help='Output jiri manifest.',
+      default=os.path.join(DART_ROOT, 'dart_third_party_pkg.manifest'))
+
+  return parser.parse_args(args)
+
+
+def Main(argv):
+  args = ParseArgs(argv)
+  deps = ParseDepsFile(args.deps)
+  WriteManifest(deps, args.output)
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(Main(sys.argv))