Get Proguard flags from GMS clients (upstream part)

build/android/play_services/preprocess.py

Index: build/android/play_services/preprocess.py
diff --git a/build/android/play_services/preprocess.py b/build/android/play_services/preprocess.py
index b14ffad8b271023f46a260424fe7583209686faf..16fd3c46764585455c2ae5fd377eeba76c4beba8 100755
--- a/build/android/play_services/preprocess.py
+++ b/build/android/play_services/preprocess.py
@@ -35,6 +35,7 @@ import shutil
 import stat
 import sys
 import tempfile
+import textwrap
 import zipfile
 
 sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir))
@@ -55,11 +56,21 @@ def main():
                                    'location'),
                              required=True,
                              metavar='FILE')
+  required_args.add_argument('-d',
+                             '--root-dir',
+                             help='the directory which GN considers the root',
+                             required=True,
+                             metavar='FILE')
   required_args.add_argument('-o',
                              '--out-dir',
                              help='the output directory',
                              required=True,
                              metavar='FILE')
+  required_args.add_argument('-g',
+                             '--gni-out-file',
+                             help='the GN output file',
+                             required=True,
+                             metavar='FILE')
   required_args.add_argument('-c',
                              '--config-file',
                              help='the config file path',
@@ -73,11 +84,14 @@ def main():
   args = parser.parse_args()
 
   return ProcessGooglePlayServices(args.repository,
+                                   args.root_dir,
                                    args.out_dir,
+                                   args.gni_out_file,
                                    args.config_file)
 
 
-def ProcessGooglePlayServices(repo, out_dir, config_path):
+def ProcessGooglePlayServices(
+    repo, root_dir, out_dir, gni_out_file, config_path):
   config = utils.ConfigParser(config_path)
 
   tmp_root = tempfile.mkdtemp()
@@ -86,6 +100,7 @@ def ProcessGooglePlayServices(repo, out_dir, config_path):
     _ImportFromExtractedRepo(config, tmp_paths, repo)
     _ProcessResources(config, tmp_paths, repo)
     _CopyToOutput(tmp_paths, out_dir)
+    _EnumerateProguardFiles(root_dir, out_dir, gni_out_file)
     _UpdateVersionInConfig(config, tmp_paths)
   finally:
     shutil.rmtree(tmp_root)
@@ -187,6 +202,37 @@ def _CopyToOutput(tmp_paths, out_dir):
   shutil.copytree(tmp_paths['imported_clients'], out_dir)
 
 
+# Write a GN file containing a list of each GMS client's proguard file (if any).
+def _EnumerateProguardFiles(root_dir, out_dir, gni_path):
+  gni_dir = os.path.dirname(gni_path)
+  gni_template = textwrap.dedent('''\
+      # Copyright 2017 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.
+
+      # This file generated by {script}
+      gms_proguard_configs = [
+      {body}
+      ]
+      ''')
+
+  gni_lines = []
+  for client_dir in os.listdir(out_dir):
+    proguard_path = os.path.join(
+        out_dir, client_dir, 'proguard.txt')
+    if os.path.exists(os.path.dirname(proguard_path)):
+      rooted_path = os.path.relpath(proguard_path, root_dir)
+      gni_lines.append('  "//{}",'.format(rooted_path))
+  gni_lines.sort()
+
+  gni_text = gni_template.format(
+      script=os.path.relpath(sys.argv[0], gni_dir),
+      body='\n'.join(gni_lines))
+
+  with open(gni_path, 'w') as gni_file:
+    gni_file.write(gni_text)
+
+
 def _UpdateVersionInConfig(config, tmp_paths):
   version_xml_path = os.path.join(tmp_paths['imported_clients'],
                                   config.version_xml_path)