Restore tools/dart/create_updated_flutter_deps.py. (#787)

An autoroller depends on this script. See
flutter/engine#47053.

Author: chinmaygarde

tools/dart/create_updated_flutter_deps.py

@@ -0,0 +1,143 @@
+#!/usr/bin/env python3
+#
+# Copyright 2017 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: tools/dart/create_updated_flutter_deps.py [-d dart/DEPS] [-f flutter/DEPS]
+#
+# This script parses existing flutter DEPS file, identifies all 'dart_' prefixed
+# dependencies, looks up revision from dart DEPS file, updates those dependencies
+# and rewrites flutter DEPS file.
+
+import argparse
+import os
+import sys
+
+DART_SCRIPT_DIR = os.path.dirname(sys.argv[0])
+DART_ROOT = os.path.realpath(os.path.join(DART_SCRIPT_DIR, '../../third_party/dart'))
+FLUTTER_ROOT = os.path.realpath(os.path.join(DART_SCRIPT_DIR, '../../flutter'))
+
+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]
+    if var_name == 'host_os':
+      return 'linux' # assume some default value
+    if var_name == 'host_cpu':
+      return 'x64' # assume some default value
+    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)
+
+  return (local_scope.get('vars', {}), local_scope.get('deps', {}))
+
+def ParseArgs(args):
+  args = args[1:]
+  parser = argparse.ArgumentParser(
+      description='A script to generate updated dart dependencies for flutter DEPS.')
+  parser.add_argument('--dart_deps', '-d',
+      type=str,
+      help='Dart DEPS file.',
+      default=os.path.join(DART_ROOT, 'DEPS'))
+  parser.add_argument('--flutter_deps', '-f',
+      type=str,
+      help='Flutter DEPS file.',
+      default=os.path.join(FLUTTER_ROOT, 'DEPS'))
+  return parser.parse_args(args)
+
+def Main(argv):
+  args = ParseArgs(argv)
+  (new_vars, new_deps) = ParseDepsFile(args.dart_deps)
+  (old_vars, old_deps) = ParseDepsFile(args.flutter_deps)
+
+  updated_vars = {}
+
+  # Collect updated dependencies
+  for (k,v) in sorted(old_vars.items()):
+    if k not in ('dart_revision', 'dart_git') and k.startswith('dart_'):
+      dart_key = k[len('dart_'):]
+      if dart_key in new_vars:
+        updated_revision = new_vars[dart_key].lstrip('@') if dart_key in new_vars else v
+        updated_vars[k] = updated_revision
+
+  # Write updated DEPS file to a side
+  updatedfilename = args.flutter_deps + ".new"
+  updatedfile = open(updatedfilename, "w")
+  file = open(args.flutter_deps)
+  lines = file.readlines()
+  i = 0
+  while i < len(lines):
+    updatedfile.write(lines[i])
+    if lines[i].startswith("  'dart_revision':"):
+      i = i + 2
+      updatedfile.writelines([
+        '\n',
+        '  # WARNING: DO NOT EDIT MANUALLY\n',
+        '  # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py\n'])
+      while i < len(lines) and len(lines[i].strip()) > 0:
+        i = i + 1
+      for (k, v) in sorted(updated_vars.items()):
+        updatedfile.write("  '%s': '%s',\n" % (k, v))
+      updatedfile.write('\n')
+
+    elif lines[i].startswith("  # WARNING: Unused Dart dependencies"):
+      updatedfile.write('\n')
+      i = i + 1
+      while i < len(lines) and (lines[i].startswith("  # WARNING: end of dart dependencies") == 0):
+        i = i + 1
+      for (k, v) in sorted(old_deps.items()):
+        if (k.startswith('src/third_party/dart/')):
+          for (dart_k, dart_v) in (list(new_deps.items())):
+            dart_k_suffix = dart_k[len('sdk/') if dart_k.startswith('sdk/') else 0:]
+            if (k.endswith(dart_k_suffix)):
+              if (isinstance(dart_v, str)):
+                updated_value = dart_v.replace(new_vars["dart_git"], "Var('dart_git') + '/")
+                updated_value = updated_value.replace(old_vars["chromium_git"], "Var('chromium_git') + '")
+
+                plain_v = dart_k[dart_k.rfind('/') + 1:]
+                # This dependency has to be special-cased here because the
+                # repository name is not the same as the directory name.
+                if plain_v == "quiver":
+                  plain_v = "quiver-dart"
+                if ('dart_' + plain_v + '_tag' in updated_vars):
+                  updated_value = updated_value[:updated_value.rfind('@')] + "' + '@' + Var('dart_" + plain_v + "_tag')"
+                elif ('dart_' + plain_v + '_rev' in updated_vars):
+                  updated_value = updated_value[:updated_value.rfind('@')] + "' + '@' + Var('dart_" + plain_v + "_rev')"
+                else:
+                  updated_value = updated_value + "'"
+              else:
+                # Non-string values(dicts) copy verbatim, keeping them sorted
+                # to ensure stable ordering of items.
+                updated_value = dict(sorted(dart_v.items()))
+
+              updatedfile.write("  '%s':\n   %s,\n\n" % (k, updated_value))
+              break
+      updatedfile.write(lines[i])
+    i = i + 1
+
+  # Rename updated DEPS file into a new DEPS file
+  os.remove(args.flutter_deps)
+  os.rename(updatedfilename, args.flutter_deps)
+
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(Main(sys.argv))